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Calculating Limits as x Goes to Infinity
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- Intro 0:00
- Limit as x Goes to Infinity 0:14
- Limit as x Goes to Infinity
- Let's Look at f(x) = 1 / (x-3)
- Summary
- Example I: Calculating Limits as x Goes to Infinity 12:16
- Example II: Calculating Limits as x Goes to Infinity 21:22
- Example III: Calculating Limits as x Goes to Infinity 24:10
- Example IV: Calculating Limits as x Goes to Infinity 36:00
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Transcription: Calculating Limits as x Goes to Infinity
Hello, welcome back to www.educator.com, and welcome back to AP Calculus.0000
Today, we are going to talk about what happens when x actually goes to infinity.0004
Calculating limits, the way that we have done for previous problems.0009
Let us jump right on in.0013
We have already seen through some examples,0016
I think I’m going to work in red today.0024
I think I might work in blue.0030
We have already seen that the following is possible.0033
We have the limit as x approaches some number a of f(x) = positive or negative infinity.0045
We know that as we get close to some number, no matter what that number is,0054
that the function itself actually just blows up to infinity.0058
They go straight up or straight down to negative infinity.0061
We have seen that already.0064
For example, the limit as x approaches 3 from above, I will just leave it as 3 from below.0064
It does not matter, of 1/ x - 3 = positive infinity.0078
Let us go ahead and draw this out.0087
That is going to be something like this.0091
We know that 3 itself is not in the domain because if it were 3, it is not defined.0094
We know that we have a vertical asymptote at 3.0100
Basically what happened is, as we approach 3 from above of this function, as we approach 3,0105
this is 3 right here, from above the function just blows up to positive infinity.0112
We also know that the limit as x approaches 3 from below of this function 1/ x – 3.0119
As we approach 3 from below, coming that way, it is going to end up going to negative infinity.0127
That is all, that is all this means.0136
As x approaches some number, the function itself goes to infinity.0140
We have also mentioned the following.0146
The limit as x approaches infinity of f(x), in other words what happens when x itself goes to infinity.0159
We can take a look at this example again.0169
This 1/ x – 3, we see that as x gets really big, the function itself just gets closer and closer to 0 from above.0171
The same thing here, as we go to negative infinity, the function just gets closer and closer to the x axis.0179
In other words, to y = 0.0186
That is something that we have also seen.0188
We used graphs and tables of values to see what happens.0193
Just like in the last example, we just look at the graph to see what happens to f(x),0208
when x goes to positive or negative infinity.0220
Now we want deal with this analytically.0224
How do we actually do it mathematically?0227
We want to deal with these analytically.0235
Let us look at the example above.0246
Let us look at f(x) = 1/ x – 3.0254
We ask ourselves, what is the limit as x approaches infinity.0261
Let us go ahead and take positive infinity of the function 1/ x – 3.0273
We already saw what happens.0279
The way you handle it analytically is essentially going to be the same thing.0282
You are basically just going to put infinity in to the function and see what happens to the function.0286
That is what you are asking yourself.0291
As x gets really big, what does the whole function do?0294
You essentially do the same thing as before.0301
Just basically plugging in, instead of plugging in a number, you are plugging in infinity.0307
You essentially do the same thing as before.0315
You plug in, I mean technically, infinity it is not a number.0323
You cannot really plug it in.0327
But again, the degree of precision here is not that big a deal, we know what is happening.0329
As long as we know what is happening, we do not have to worry about pedantic little issues like this.0337
Basically, again, just plug in infinity and ask what does the function do.0342
Let me see, should I do the same thing as before?0350
Plugging in just means take x very large in the positive or negative direction and ask how the function behaves.0352
Let us do it this way, for the limit as x approaches positive infinity of 1/ x – 3.0397
When we put in infinity here, as x goes to positive infinity, the denominator gets really big.0410
The denominator gets very large.0427
Now as the denominator gets very large, what about the function itself, 1/ the denominator.0431
As the denominator gets large, the function itself gets really small.0438
Because the denominator is a bigger and bigger and bigger number.0441
1/ 1000, 1/ 100000, 1/10000000, it is going to 0.0444
As the denominator gets huge, 1/ x - 3 gets very small.0448
It approaches 0, that is what is happening.0469
That is all what we have been doing, the same thing.0474
You are essentially just going to plug it in and see what happens.0477
If you get an answer, you are good.0481
If you get something that does not make sense, you are going to have to do the same as before.0482
You are going to have to basically manipulate the expression and then take the limit again0486
as x goes to positive or negative infinity, whichever they are asking for.0489
That is the basic process over and over again.0492
We say the limit as x approaches positive infinity of 1/ x - 3 = 0.0501
The same thing with negative infinity.0511
What about the limit as x approaches negative infinity of 1/ x – 3.0519
The same thing, if we put a negative infinity in here, it is going to be a big number in the dominator.0524
It is going to be a very small function.0529
Essentially, it is going to go to 0.0532
We say it approaches 0, it just approaches it from a different point.0535
Negative infinity, these numbers in the denominator are going to be negative.0539
A positive number 1 divided by a negative number, it is going to be a negative number.0543
It is going to approach infinity from below.0546
Up here, as you go towards infinity, it approaches infinity from above.0550
That is the only difference, that vs. that.0554
They both approach 0 but from opposite ends, from the top and from the bottom.0560
Nothing strange, pretty intuitive stuff here.0573
We essentially do the same thing.0577
Sorry, I keep repeating myself.0580
We essentially do the same thing.0587
You plug in positive or negative infinity and ask what happens.0588
Again, when we say plug in positive or negative infinity, we are saying as infinity gets really big,0600
what does the function do.0605
If you get something, we essentially do the same thing, as what happens.0609
If we get something that makes sense like a number, an actual limit, that something approaches, we can stop, that is our answer.0627
We can stop, this is our answer.0643
If we get something that does not make sense, then we manipulate the expression and take the limit again.0652
Manipulate the expression and take that limit again.0683
The same limit, the limit as x goes to positive or negative infinity.0693
I wonder if I should write down what i have here next.0719
You know what, let us just launch right into the examples.0723
I think that is probably the best approach.0729
Let me go ahead and do example here.0734
We want to know what the limit is, as x approaches infinity of this rational function 7x² - 3x + 14/ 5x² + 2x + 6.0740
As x goes to infinity, the numerator goes to infinity, the denominator goes to infinity.0761
You are going to end up with this thing, infinity/ infinity.0766
This does not make sense, we are going to have to do something to this expression.0769
When you see 0/0, infinity/ infinity, infinity – infinity, because we actually do not know the rates at which these two go to infinity,0775
we do not if it actually converges to a limit or not.0783
That is why it is indeterminate.0789
You might be thinking to yourself, this one goes to infinity, this one goes to infinity, is not just 1?0790
No, it is not 1 because we do not know the rate at which these go to infinity.0794
It is indeterminate.0802
Here is how you handle a rational function.0803
For rational functions which this is, rational functions, the manipulation is the same.0806
We manipulate by dividing both the numerator and denominator by the highest power of x in the denominator.0820
In this case, the denominator, the highest power is x².0854
We are going to multiply top and bottom by x².0857
Here it is x².0863
What we get is the following.0869
We get the limit as x approaches infinity.0870
When we divide the top by x², we get 7 +,0875
Let me write up the whole thing.0884
7x² - 3x + 14/ x² divided by 5x² + 2x + 6/ x².0889
I have not changed the expression, I just multiplied the top and bottom by 1/ x².0902
This becomes the limit as x goes to infinity of 7 + 3/ x + 14x²/ 5 + 2/ x + 6/ x².0906
I just divided the x² into everything.0932
And now I take the limit again, as x goes to infinity.0935
Now I have an x in the denominator and a number on top.0938
As x goes to infinity, this goes to 0, this goes to 0, this goes to 0, this goes to 0.0941
I’m just left with 7/5, that is my limit.0948
That is how you do it.0952
Whenever you are dealing with a rational function, just divide top and bottom by the highest power in the denominator.0954
And then, take the limit again and that should give you your answer.0959
You can also have done the following with rational functions.0966
As x gets really big, whether positive or negative, basically,0971
the term that is going to dominate is going to be the highest powers in their respective polynomials.0974
In the top, the term that is going to dominate is 7x² term.0979
These basically drop out.0984
They do not contribute much.0985
In the bottom, the 5x² + 2x + 6, this term is going to dominate.0988
It drops out.0992
What you are left with is, the limit as x goes to infinity of 7x²/ 5x² which is the limit as x goes to infinity of 7/5.0994
We know that the limit of the constant is just the constant itself.1008
You can do it that way as well, absolutely fine.1011
Just ignore the lower degree of x and just worry about the highest degree x, and take it from there.1014
That is an alternate way of doing this.1023
Either one is fine, whichever works for you.1026
Let us go ahead and state the following.1030
When the limit as x goes to positive or negative infinity.1041
When you take a limit as x goes to infinity and you actually get a finite number that we got, like we got here, the 7/5, a number,1047
when a limit as x goes to infinity is an actual number, this number is a horizontal asymptote.1055
This number is a horizontal asymptote.1066
It is a horizontal, just like when we have rational functions like 1/ x – 3, the denominator,1075
the 3 is going to be a vertical asymptote because it is not defined at 3.1080
3 – 3 gives us 0.1084
When we take limits to infinity, if those limits actually give us finite numbers, those are horizontal asymptotes.1086
Let us take a look at what this particular function looks like.1094
It looks like this.1098
We see that as x goes to infinity, positive infinity or negative infinity, does not matter.1099
Let us just do it over here.1107
As x approaches positive infinity, this is the graph of the function.1114
As x gets bigger, we see that the function is actually approaching the horizontal asymptote1119
which is the dashed line, which is the 7/5.1126
This line is y = 7/5 and this of course is y = f(x), that rational function that we just worked out.1129
As x goes to positive infinity, f(x) goes to 7/5.1138
The same thing over here.1146
As x goes to negative infinity, f(x) actually approaches the same value 7/5.1148
That is all that is happening here.1156
A couple of things to notice, notice that the function drops below, crosses the asymptote,1162
and then comes up and approaches 0.1178
That is not a problem.1181
When we take limits to infinity, we are not concerned about what happens in the center of the graph.1182
We are only concerned about what happens as x gets really big, positive or negative.1187
It is not a problem for a function to actually cross a horizontal asymptote.1192
It can actually cross as many times as it likes.1198
When you deal with trigonometric functions, you might see trigonometric and exponential functions.1201
You might see that it actually crosses several times1208
but it actually gets closer and closer to some actual number to a horizontal asymptote.1211
A horizontal asymptote exists, a limit exists, but it is okay is it crosses it.1218
We are asking what happens to the function, as we get bigger and bigger.1223
In other words, is it approaching some number.1226
Do not worry about crossing the asymptote.1228
Let us write that down.1236
Crossing a horizontal asymptote is not a problem, as long as f(x) approaches some number closer and closer.1237
There you go, now we have the graphical, we have the tabular, if you need that.1270
Now we have the analytical.1276
Let us do another example here.1281
The limit as x goes to infinity 3x³ - 2x² + 4x + 14.1285
This one is easy, straight polynomial.1302
This one is easy, as x goes to positive infinity, f(x) goes to positive infinity.1310
Let us do it this way.1325
Let us deal with the highest degree.1327
As x gets really big and big, the only term that is going to dominate is going to be this term, the 3x³.1330
We do not have to worry about those.1335
As x goes to positive infinity, a positive number cubed is a positive number.1338
F(x) is going to go to positive infinity.1342
As x goes to negative infinity, this is going to dominate.1350
A negative number cubed is a negative number.1357
Therefore, f(x) itself is going to end up going towards negative infinity.1359
That is all that is going on here.1365
Notice, as x goes to positive infinity, f(x) goes to positive infinity.1376
As x goes to negative infinity, f(x) goes to negative infinity.1381
This does not actually converge to a number.1385
The functions just fly off in opposite directions.1387
This function does not converge to an actual number.1390
That can happen, we know that already.1407
We have seen limit as x approaches some number can be some number, an actual limit.1413
The limit as x approaches some number, the function can go off to infinity.1419
Now x itself can go off to positive or negative infinity.1425
The function itself can approach some number, an actual limit.1428
The limit exists, in other words.1433
Or as x goes to positive or negative infinity, the function goes to positive or negative infinity.1434
Those are the possibilities.1439
Let us do another example.1447
This is going to be slightly more involved and it is definitely an example that you want to pay close attention to.1449
The limit as x approaches infinity of 15x² + 30 all under the radical sign/ x - 1.1456
We have a rational function.1470
There is a square root on the top but it is still a rational function and some function on top/ some function on the bottom.1472
Again, a rational function, our general procedure for dealing with a rational function,1485
it implies that we divide the top and bottom by the highest degree of x in the denominator.1494
We divide the numerator and denominator by the highest power of x in the denominator.1501
Now x going to infinity means x goes to positive infinity and x goes to negative infinity.1528
I have to let you know something.1539
Some people, when you see x goes to infinity, they are saying goes to positive infinity.1541
Remember what we said in the previous lesson.1547
When you are dealing with limits as x goes to infinity, we deal with those separately.1548
x = positive infinity, x = negative infinity.1552
Here in some books and in some classes, when people say x goes to infinity, they mean positive infinity.1555
They do not mean the negative.1563
In this case, when I write x = goes to infinity, I will specify whether I mean just positive infinity, or in this case,1564
it means break it up into both its positive and negative infinity.1571
Beware of that distinction.1575
We do both.1582
Let us deal with x being greater than 0, in other words, x going to positive infinity.1587
x is greater than 0.1593
Like we said, we divide the top and bottom by the highest power.1596
We are going to get 15x² + 30 under the radical/ x/ x - 1/ x.1600
This is going to equal, x, I can think of it as √x².1611
15x² + 30, under the radical/ √x².1618
I’m just rewriting x as the √x².1625
All over here, I divide 1 - 1/ x.1629
Since this is a radical and this is a radical, I combine the radicals.1634
This is going to end up equaling 15x² + 30/ x² under the radical, /1 - 1/ x.1638
I do the actual division, now that I’m under one radical.1651
I get √15 + 30/ x²/ 1 – 1/ x.1653
This is my particular manipulation.1664
Now that I have a manipulation, now I take the limit.1667
We take the limit as x approaches positive infinity.1676
The limit as x approaches positive infinity of 15 + 30/ x² under the radical, / 1 - 1/ x.1686
As x goes to infinity, 30/ x² goes to 0 because x² blows up.1698
The denominator, it is only a constant on top, it is going to go to 0.1704
1/ x as x goes to infinity goes to 0.1708
We are left with √15.1711
√15 is our limit as x goes to positive infinity.1714
Let us deal with x less than 0.1719
X goes to negative infinity.1721
For x less than 0, it gets a little strange.1726
We still have the same thing.1737
We still have the 15x² + 30/ x, same thing, / x - 1 divided by x, dividing by the highest power of x in the denominator.1738
We are going to do the same thing that we did before.1751
Except, we are going to have 15x² + 30/ √x²/ x - 1/ x.1754
This is exactly the same thing that we did before, except for one thing, now because x is less than 0.1766
This is x and we turn it into x² as a manipulation.1775
Because x is √x², we put a negative sign here.1779
The reason we do that is the following.1783
The reason for this negative sign, I will say notice this negative sign which was not there, when we took x positive.1786
Here is why.1801
The √x², it does not actually equal x.1809
The square root of x² actually equals, we know this from algebra and pre-calculus.1814
But we do not deal with it that much, that is the problem.1821
The √x² actually equals the absolute value of x.1823
The absolute value of x is equal to x, when x is greater than 0.1828
Or it equals negative x, when x is less than 0.1835
This negative sign has to be brought in, when you are dealing with x less than 0.1839
When you turn this x into a √x², this is actually an absolute value of x.1844
That absolute value of x is a –x, that comes out here.1851
That is what is going on here.1855
I hope that makes sense.1861
It is a little strange, probably you have to think about it for a little bit but that is what is happening.1863
The reason being that the √x² is not just x.1867
It is actually the absolute value of x, because when x is negative, you can square it.1876
You can still get a positive number that you can take the square root of.1881
You have to account for x being negative or x being positive.1884
That is why this negative sign have to show up, when we are dealing with x1888
which is less than 0 because of the definition of the absolute value.1892
I hope that makes sense, in any case.1896
Now we have that expression.1899
We have -15x² + 30 under the radical, / √x²/ x - 1/ x = -15x² + 30/ x² / 1 – 1/ x.1902
All of that = -√15 - 30/ x² / 1 - 1/ x.1929
Now we take the limit.1940
The limit as x approaches -infinity of -15 -,1943
Was it – or +, I think it is + actually + 30/ x² / 1 - 1/ x.1953
As x goes to negative infinity, 30/ x² goes to 0, 1/ x goes to 0.1960
We are left with -√15 is the limit.1968
Now when we took x to positive infinity, our horizontal asymptote was √15.1975
As x goes to negative infinity, our horizontal asymptote is -√15.1984
You have two horizontal asymptotes.1989
The function is behaving differently.1991
It is approaching two different numbers, as you go big to the right and big to the left.1993
The function f(x) = the original function is 30/ x - 1 has two horizontal asymptotes.2006
y = √15 and y = -√15.2030
Let us take a look and see what this actually looks like.2038
It is going to look like this.2042
This is our function and the dashed lines are going to be the horizontal and vertical asymptotes.2043
This line right here, this is your y = √15.2051
This line right here is y = -√15.2057
I hope that makes sense.2064
Notice we also happen to have a vertical asymptote because of the x – 1 in the denominator.2067
Here, this is our vertical asymptote.2072
But as the function, here is the 0,0 mark right here.2080
As x gets really big, the function, as you can see, gets closer and closer and closer to √15.2085
As x gets really big, negative goes to negative infinity.2094
The function crosses and then comes back down, and gets closer and closer and closer and closer to -√15.2099
Whenever you see radicals in rational functions, things like this are going to happen.2108
You just have to be careful.2113
Again, let us recall that √x² actually = the absolute value of x.2114
The absolute value of x is equal to regular x, when x is greater than 0.2121
In other words, when you are going to positive infinity but it is equal to –x, when x is less than 0.2126
When you are going to negative infinity.2132
You have to have that extra negative sign.2134
It is going to confuse the heck out of you and do not worry about it.2137
To this day, I still make mistakes with stuff like this.2140
Which is why personally, I love graphs.2144
I make the graph and the graph tells me exactly what my function is doing.2147
And then, I adjust my analysis in order to fit the graph.2150
It is cheating but c'est la vie.2155
Let us do another, an example.2160
What is the limit as x approaches 0 of e¹/x.2167
This is a number, x = 0.2181
We have to do x approaches 0 from above.2183
We have to do x approaches 0 from below.2191
For x approaching 0 from above, positive numbers headed towards 0, here is what we get.2197
As x gets close to 0, this 1/x goes to positive infinity.2208
As x gets tinier and tinier, 1/ 1/10, 1/ 1/100, 1/ 1/1000000, the 1/x blows up to infinity.2220
We get e ⁺infinity = infinity.2232
The limit as x approaches 0 from above of e¹/x = positive infinity.2240
For x approaches 0 from below, as x approaches 0 from below,2253
x is a negative number that means 1/x goes to negative infinity.2269
x is a negative number.2281
It is getting closer to 0 but it is still a negative number.2283
1/x is a negative number.2288
It is going to end up going towards negative infinity.2290
1/x goes to negative infinity.2293
e ⁺negative infinity is equivalent to 1/ e ⁺infinity.2298
1/e, as this becomes infinitely large, the 1/x becomes infinitely small.2310
It goes to 0.2318
The limit as x approaches 0 from below of e¹/x is actually equal to 0.2323
You get two different limits approaching a number one from above and one from below.2333
Again, it is all based on just asking yourself what happens to the function, or in this case, pieces of the function.2339
You use that piece to address the big function, when x does something.2346
Use your intuition, trust your intuition.2351
This is completely intuitive.2354
I know the x is negative.2358
Therefore, I know that 1/x is going to be a negative number.2360
If it gets closer and closer to 0, it is going to go off to infinity but it is going to go off to negative infinity.2363
e ⁻infinity is the same as 1/ e ⁺infinity.2371
As this denominator gets big, the function itself, it goes to 0.2374
Let us take a look and see what is this.2382
In this case, the limit as x approaches 0 of e¹/x does not exist.2387
It does not exist because you ended up with two different limits.2397
One is infinite, one is 0.2400
Again, we said, when you are approaching a number,2402
the left hand limit and the right hand limit have to be the same, in order for us to say that the limit exists.2405
The limit is this.2410
Our left hand limit exists at 0, the right hand limit hand limit exists in the sense that it goes off to infinity.2415
It is not a real number but they exist, it goes off to infinity.2421
But the limit itself does not exist.2424
Let me repeat, I know you are sick to death of me repeating this, I know.2431
You see that we are simply asking ourselves,2437
what happens to f(x) as x either approaches a number or as x approaches infinity.2455
That is all we are asking.2472
The reason I keep repeating myself, I apologize, is because sometimes2473
when you are just faced with some function, it is a little intimidating symbolically.2477
You sort of all of a sudden get a little intimidated and discombobulated, just what is it asking.2481
It is saying, as x does this, what does f(x) do?2488
Just remember that is all this symbolism is.2493
As x does this, what does f(x) do?2496
As long as you contain that, you can calm down and address the issue as you need to.2499
Essentially, it is simple.2505
The hardest part in taking limits is going to be the manipulation part.2507
How do I manipulate the function, in order to actually be able to take the limit and get something that makes sense.2510
It is always going to be the hardest part of calculus.2517
It is going to be the manipulation and the algebra, not the calculus itself.2519
In any case, that is that.2523
I will write this out.2536
If our first attempt is nonsense, when we take the limit nonsense,2538
then we manipulate and try again until we get f(x) actually approaches an actual number,2549
or we get f(x) going to positive or negative infinity.2576
If it does not work the second time, when you take the limit after you manipulate it, try another manipulation.2580
Try it again, you keep trying until one of these two things happens.2584
Either you end up with an actual number, when you take the limit, or you end up with positive or negative infinity.2588
That is when you can stop.2592
Let us try, this time, the limits as x goes to positive or negative infinity of e¹/x.2598
Now it is not x approaches 0, but it is x approaches positive or negative infinity of e¹/x.2609
Let us see what happens here.2615
As x approaches positive infinity, let us go ahead and write our function again here.2623
f(x) = e¹/x, actually let me write the entire limit.2638
We wanted to know what the limit as x approaches positive or negative infinity was, of e¹/x.2645
As x approaches positive infinity, 1/x goes to 0.2651
e¹/x, e⁰ approaches 1 from above, positive numbers.2663
As x approaches negative infinity, 1/x definitely approaches 0.2675
1/x approaches 0, with 1/x being negative values.2700
e¹/x is equivalent to 1/,2710
Let me make this more clear.2727
As x goes to negative infinity, this 1/x, it goes to 0 through negative values.2728
Because if x is a negative number then 1/x is a negative number, two negative values.2735
e⁻¹/x.2749
You know what, I do not want to do that.2757
We are still dealing with e¹/x.2760
e¹/x, except now this 1/x is our negative numbers.2761
That is going to be equal to 1/ e¹/x, where now these are positive.2767
e¹/x, we said that it approaches 1, this is going to approach 1/1.2775
It is going to be 1 from below.2784
The morale of all this is just keep track of all the details.2788
Just be really meticulous in what is it that you do and everything should work out.2792
Let us take a look at what this particular thing looks like.2796
This is our function.2799
Here our function is e¹/x.2802
As x gets really big positive, we said that the function itself is going to approach 1.2806
This dashed line is our horizontal asymptote, it is y = 1.2813
As x gets really big negative, 1/x is definitely going to be negative.2820
It is the same as 1/ e¹/x, it is going to also approach 1 from below.2828
But notice it never becomes negative because this is never a negative number.2835
It approaches it from below but still positive numbers, in the sense that.2842
1/x is negative, the e¹/x which is what this function is, it approaches 1 from below.2847
In this case, there is only one horizontal asymptote.2854
It is y = 1.2857
The lesson is basically this, there is no one way to evaluate every limit.2868
That is pretty much where it comes down to.2888
This is reasonably sophisticated mathematics.2890
As things become more sophisticated in mathematics, it is no longer going to be algorithmic.2892
There is a certain degree of algorithm, or if you do this and this, each problem is going to be different.2898
You have to bring all your resources to bare, whatever those resources are.2903
Whether they be graphs, tables, analytics, some trick that you learn when you are 10 years old, whatever it happens to be.2907
All of these things have to be brought to bare, as weapons against these particular problem.2916
There is no one way to evaluate every limit.2921
Do not think that you are supposed to just look at a problem and know how to do it.2925
The process of mathematics is not looking at it and just automatically knowing what to do.2928
If you fall into that trap, then when you are faced with something that is slightly different than what you used to,2936
you are not going to able to handle it.2941
Always try to keep a reasonable degree of objectivity.2943
Keep an open mind and do not worry that all of a sudden you look at something,2945
you do not know how to do it immediately.2949
Knowing how to do something immediately is not a measure of intelligence.2952
Intelligence has to do with being able to look at a situation and work the situation out.2958
This is sophisticated mathematics, it is not 1 or 2 steps.2964
There are going to be some problems in calculus over the next year that are multiple steps.2967
You are not going to even know where it is that you are going.2972
You are going to have to trust each step you take is a reasonable step.2974
You are going to have to hope that it is taking you somewhere.2978
That is what it is about, it is about getting to the answer in a reasonable logical way.2980
Even if you do not know exactly the path that you are following.2985
It could be a very circuitous path, in any case.2988
There is no one way to evaluate every limit.2992
Use every resource at your disposal.2996
Thank you so much for joining us here at www.educator.com.2998
We will see you next time, bye.3000

Raffi Hovasapian
Calculating Limits as x Goes to Infinity
Slide Duration:Table of Contents
42m 8s
- Intro0:00
- Overview & Slopes of Curves0:21
- Differential and Integral0:22
- Fundamental Theorem of Calculus6:36
- Differentiation or Taking the Derivative14:24
- What Does the Derivative Mean and How do We Find it?15:18
- Example: f'(x)19:24
- Example: f(x) = sin (x)29:16
- General Procedure for Finding the Derivative of f(x)37:33
50m 53s
- Intro0:00
- Slope of the Secant Line along a Curve0:12
- Slope of the Tangent Line to f(x) at a Particlar Point0:13
- Slope of the Secant Line along a Curve2:59
- Instantaneous Slope6:51
- Instantaneous Slope6:52
- Example: Distance, Time, Velocity13:32
- Instantaneous Slope and Average Slope25:42
- Slope & Rate of Change29:55
- Slope & Rate of Change29:56
- Example: Slope = 233:16
- Example: Slope = 4/334:32
- Example: Slope = 4 (m/s)39:12
- Example: Density = Mass / Volume40:33
- Average Slope, Average Rate of Change, Instantaneous Slope, and Instantaneous Rate of Change47:46
59m 12s
- Intro0:00
- Example I: Water Tank0:13
- Part A: Which is the Independent Variable and Which is the Dependent?2:00
- Part B: Average Slope3:18
- Part C: Express These Slopes as Rates-of-Change9:28
- Part D: Instantaneous Slope14:54
- Example II: y = √(x-3)28:26
- Part A: Calculate the Slope of the Secant Line30:39
- Part B: Instantaneous Slope41:26
- Part C: Equation for the Tangent Line43:59
- Example III: Object in the Air49:37
- Part A: Average Velocity50:37
- Part B: Instantaneous Velocity55:30
18m 43s
- Intro0:00
- Desmos Tutorial1:42
- Desmos Tutorial1:43
- Things You Must Learn To Do on Your Particular Calculator2:39
- Things You Must Learn To Do on Your Particular Calculator2:40
- Example I: y=sin x4:54
- Example II: y=x³ and y = d/(dx) (x³)9:22
- Example III: y = x² {-5 <= x <= 0} and y = cos x {0 < x < 6}13:15
51m 53s
- Intro0:00
- The Limit of a Function0:14
- The Limit of a Function0:15
- Graph: Limit of a Function12:24
- Table of Values16:02
- lim x→a f(x) Does not Say What Happens When x = a20:05
- Example I: f(x) = x²24:34
- Example II: f(x) = 727:05
- Example III: f(x) = 4.530:33
- Example IV: f(x) = 1/x34:03
- Example V: f(x) = 1/x²36:43
- The Limit of a Function, Cont.38:16
- Infinity and Negative Infinity38:17
- Does Not Exist42:45
- Summary46:48
24m 43s
- Intro0:00
- Example I: Explain in Words What the Following Symbols Mean0:10
- Example II: Find the Following Limit5:21
- Example III: Use the Graph to Find the Following Limits7:35
- Example IV: Use the Graph to Find the Following Limits11:48
- Example V: Sketch the Graph of a Function that Satisfies the Following Properties15:25
- Example VI: Find the Following Limit18:44
- Example VII: Find the Following Limit20:06
53m 48s
- Intro0:00
- Plug-in Procedure0:09
- Plug-in Procedure0:10
- Limit Laws9:14
- Limit Law 110:05
- Limit Law 210:54
- Limit Law 311:28
- Limit Law 411:54
- Limit Law 512:24
- Limit Law 613:14
- Limit Law 714:38
- Plug-in Procedure, Cont.16:35
- Plug-in Procedure, Cont.16:36
- Example I: Calculating Limits Mathematically20:50
- Example II: Calculating Limits Mathematically27:37
- Example III: Calculating Limits Mathematically31:42
- Example IV: Calculating Limits Mathematically35:36
- Example V: Calculating Limits Mathematically40:58
- Limits Theorem44:45
- Limits Theorem 144:46
- Limits Theorem 2: Squeeze Theorem46:34
- Example VI: Calculating Limits Mathematically49:26
21m 22s
- Intro0:00
- Example I: Evaluate the Following Limit by Showing Each Application of a Limit Law0:16
- Example II: Evaluate the Following Limit1:51
- Example III: Evaluate the Following Limit3:36
- Example IV: Evaluate the Following Limit8:56
- Example V: Evaluate the Following Limit11:19
- Example VI: Calculating Limits Mathematically13:19
- Example VII: Calculating Limits Mathematically14:59
50m 1s
- Intro0:00
- Limit as x Goes to Infinity0:14
- Limit as x Goes to Infinity0:15
- Let's Look at f(x) = 1 / (x-3)1:04
- Summary9:34
- Example I: Calculating Limits as x Goes to Infinity12:16
- Example II: Calculating Limits as x Goes to Infinity21:22
- Example III: Calculating Limits as x Goes to Infinity24:10
- Example IV: Calculating Limits as x Goes to Infinity36:00
36m 31s
- Intro0:00
- Example I: Calculating Limits as x Goes to Infinity0:14
- Example II: Calculating Limits as x Goes to Infinity3:27
- Example III: Calculating Limits as x Goes to Infinity8:11
- Example IV: Calculating Limits as x Goes to Infinity14:20
- Example V: Calculating Limits as x Goes to Infinity20:07
- Example VI: Calculating Limits as x Goes to Infinity23:36
53m
- Intro0:00
- Definition of Continuity0:08
- Definition of Continuity0:09
- Example: Not Continuous3:52
- Example: Continuous4:58
- Example: Not Continuous5:52
- Procedure for Finding Continuity9:45
- Law of Continuity13:44
- Law of Continuity13:45
- Example I: Determining Continuity on a Graph15:55
- Example II: Show Continuity & Determine the Interval Over Which the Function is Continuous17:57
- Example III: Is the Following Function Continuous at the Given Point?22:42
- Theorem for Composite Functions25:28
- Theorem for Composite Functions25:29
- Example IV: Is cos(x³ + ln x) Continuous at x=π/2?27:00
- Example V: What Value of A Will make the Following Function Continuous at Every Point of Its Domain?34:04
- Types of Discontinuity39:18
- Removable Discontinuity39:33
- Jump Discontinuity40:06
- Infinite Discontinuity40:32
- Intermediate Value Theorem40:58
- Intermediate Value Theorem: Hypothesis & Conclusion40:59
- Intermediate Value Theorem: Graphically43:40
- Example VI: Prove That the Following Function Has at Least One Real Root in the Interval [4,6]47:46
40m 2s
- Intro0:00
- Derivative0:09
- Derivative0:10
- Example I: Find the Derivative of f(x)=x³2:20
- Notations for the Derivative7:32
- Notations for the Derivative7:33
- Derivative & Rate of Change11:14
- Recall the Rate of Change11:15
- Instantaneous Rate of Change17:04
- Graphing f(x) and f'(x)19:10
- Example II: Find the Derivative of x⁴ - x²24:00
- Example III: Find the Derivative of f(x)=√x30:51
53m 45s
- Intro0:00
- Example I: Find the Derivative of (2+x)/(3-x)0:18
- Derivatives II9:02
- f(x) is Differentiable if f'(x) Exists9:03
- Recall: For a Limit to Exist, Both Left Hand and Right Hand Limits Must Equal to Each Other17:19
- Geometrically: Differentiability Means the Graph is Smooth18:44
- Example II: Show Analytically that f(x) = |x| is Nor Differentiable at x=020:53
- Example II: For x > 023:53
- Example II: For x < 025:36
- Example II: What is f(0) and What is the lim |x| as x→0?30:46
- Differentiability & Continuity34:22
- Differentiability & Continuity34:23
- How Can a Function Not be Differentiable at a Point?39:38
- How Can a Function Not be Differentiable at a Point?39:39
- Higher Derivatives41:58
- Higher Derivatives41:59
- Derivative Operator45:12
- Example III: Find (dy)/(dx) & (d²y)/(dx²) for y = x³49:29
31m 38s
- Intro0:00
- Example I: Sketch f'(x)0:10
- Example II: Sketch f'(x)2:14
- Example III: Find the Derivative of the Following Function sing the Definition3:49
- Example IV: Determine f, f', and f'' on a Graph12:43
- Example V: Find an Equation for the Tangent Line to the Graph of the Following Function at the Given x-value13:40
- Example VI: Distance vs. Time20:15
- Example VII: Displacement, Velocity, and Acceleration23:56
- Example VIII: Graph the Displacement Function28:20
47m 35s
- Intro0:00
- Differentiation of Polynomials & Exponential Functions0:15
- Derivative of a Function0:16
- Derivative of a Constant2:35
- Power Rule3:08
- If C is a Constant4:19
- Sum Rule5:22
- Exponential Functions6:26
- Example I: Differentiate7:45
- Example II: Differentiate12:38
- Example III: Differentiate15:13
- Example IV: Differentiate16:20
- Example V: Differentiate19:19
- Example VI: Find the Equation of the Tangent Line to a Function at a Given Point12:18
- Example VII: Find the First & Second Derivatives25:59
- Example VIII27:47
- Part A: Find the Velocity & Acceleration Functions as Functions of t27:48
- Part B: Find the Acceleration after 3 Seconds30:12
- Part C: Find the Acceleration when the Velocity is 030:53
- Part D: Graph the Position, Velocity, & Acceleration Graphs32:50
- Example IX: Find a Cubic Function Whose Graph has Horizontal Tangents34:53
- Example X: Find a Point on a Graph42:31
47m 25s
- Intro0:00
- The Product, Power and Quotient Rules0:19
- Differentiate Functions0:20
- Product Rule5:30
- Quotient Rule9:15
- Power Rule10:00
- Example I: Product Rule13:48
- Example II: Quotient Rule16:13
- Example III: Power Rule18:28
- Example IV: Find dy/dx19:57
- Example V: Find dy/dx24:53
- Example VI: Find dy/dx28:38
- Example VII: Find an Equation for the Tangent to the Curve34:54
- Example VIII: Find d²y/dx²38:08
41m 8s
- Intro0:00
- Derivatives of the Trigonometric Functions0:09
- Let's Find the Derivative of f(x) = sin x0:10
- Important Limits to Know4:59
- d/dx (sin x)6:06
- d/dx (cos x)6:38
- d/dx (tan x)6:50
- d/dx (csc x)7:02
- d/dx (sec x)7:15
- d/dx (cot x)7:27
- Example I: Differentiate f(x) = x² - 4 cos x7:56
- Example II: Differentiate f(x) = x⁵ tan x9:04
- Example III: Differentiate f(x) = (cos x) / (3 + sin x)10:56
- Example IV: Differentiate f(x) = e^x / (tan x - sec x)14:06
- Example V: Differentiate f(x) = (csc x - 4) / (cot x)15:37
- Example VI: Find an Equation of the Tangent Line21:48
- Example VII: For What Values of x Does the Graph of the Function x + 3 cos x Have a Horizontal Tangent?25:17
- Example VIII: Ladder Problem28:23
- Example IX: Evaluate33:22
- Example X: Evaluate36:38
24m 56s
- Intro0:00
- The Chain Rule0:13
- Recall the Composite Functions0:14
- Derivatives of Composite Functions1:34
- Example I: Identify f(x) and g(x) and Differentiate6:41
- Example II: Identify f(x) and g(x) and Differentiate9:47
- Example III: Differentiate11:03
- Example IV: Differentiate f(x) = -5 / (x² + 3)³12:15
- Example V: Differentiate f(x) = cos(x² + c²)14:35
- Example VI: Differentiate f(x) = cos⁴x +c²15:41
- Example VII: Differentiate17:03
- Example VIII: Differentiate f(x) = sin(tan x²)19:01
- Example IX: Differentiate f(x) = sin(tan² x)21:02
25m 32s
- Intro0:00
- Example I: Differentiate f(x) = sin(cos(tanx))0:38
- Example II: Find an Equation for the Line Tangent to the Given Curve at the Given Point2:25
- Example III: F(x) = f(g(x)), Find F' (6)4:22
- Example IV: Differentiate & Graph both the Function & the Derivative in the Same Window5:35
- Example V: Differentiate f(x) = ( (x-8)/(x+3) )⁴10:18
- Example VI: Differentiate f(x) = sec²(12x)12:28
- Example VII: Differentiate14:41
- Example VIII: Differentiate19:25
- Example IX: Find an Expression for the Rate of Change of the Volume of the Balloon with Respect to Time21:13
52m 31s
- Intro0:00
- Implicit Differentiation0:09
- Implicit Differentiation0:10
- Example I: Find (dy)/(dx) by both Implicit Differentiation and Solving Explicitly for y12:15
- Example II: Find (dy)/(dx) of x³ + x²y + 7y² = 1419:18
- Example III: Find (dy)/(dx) of x³y² + y³x² = 4x21:43
- Example IV: Find (dy)/(dx) of the Following Equation24:13
- Example V: Find (dy)/(dx) of 6sin x cos y = 129:00
- Example VI: Find (dy)/(dx) of x² cos² y + y sin x = 2sin x cos y31:02
- Example VII: Find (dy)/(dx) of √(xy) = 7 + y²e^x37:36
- Example VIII: Find (dy)/(dx) of 4(x²+y²)² = 35(x²-y²)41:03
- Example IX: Find (d²y)/(dx²) of x² + y² = 2544:05
- Example X: Find (d²y)/(dx²) of sin x + cos y = sin(2x)47:48
47m 34s
- Intro0:00
- Linear Approximations & Differentials0:09
- Linear Approximations & Differentials0:10
- Example I: Linear Approximations & Differentials11:27
- Example II: Linear Approximations & Differentials20:19
- Differentials30:32
- Differentials30:33
- Example III: Linear Approximations & Differentials34:09
- Example IV: Linear Approximations & Differentials35:57
- Example V: Relative Error38:46
45m 33s
- Intro0:00
- Related Rates0:08
- Strategy for Solving Related Rates Problems #10:09
- Strategy for Solving Related Rates Problems #21:46
- Strategy for Solving Related Rates Problems #32:06
- Strategy for Solving Related Rates Problems #42:50
- Strategy for Solving Related Rates Problems #53:38
- Example I: Radius of a Balloon5:15
- Example II: Ladder12:52
- Example III: Water Tank19:08
- Example IV: Distance between Two Cars29:27
- Example V: Line-of-Sight36:20
37m 17s
- Intro0:00
- Example I: Shadow0:14
- Example II: Particle4:45
- Example III: Water Level10:28
- Example IV: Clock20:47
- Example V: Distance between a House and a Plane29:11
40m 44s
- Intro0:00
- Maximum & Minimum Values of a Function, Part 10:23
- Absolute Maximum2:20
- Absolute Minimum2:52
- Local Maximum3:38
- Local Minimum4:26
- Maximum & Minimum Values of a Function, Part 26:11
- Function with Absolute Minimum but No Absolute Max, Local Max, and Local Min7:18
- Function with Local Max & Min but No Absolute Max & Min8:48
- Formal Definitions10:43
- Absolute Maximum11:18
- Absolute Minimum12:57
- Local Maximum14:37
- Local Minimum16:25
- Extreme Value Theorem18:08
- Theorem: f'(c) = 024:40
- Critical Number (Critical Value)26:14
- Procedure for Finding the Critical Values of f(x)28:32
- Example I: Find the Critical Values of f(x) x + sinx29:51
- Example II: What are the Absolute Max & Absolute Minimum of f(x) = x + 4 sinx on [0,2π]35:31
40m 44s
- Intro0:00
- Example I: Identify Absolute and Local Max & Min on the Following Graph0:11
- Example II: Sketch the Graph of a Continuous Function3:11
- Example III: Sketch the Following Graphs4:40
- Example IV: Find the Critical Values of f (x) = 3x⁴ - 7x³ + 4x²6:13
- Example V: Find the Critical Values of f(x) = |2x - 5|8:42
- Example VI: Find the Critical Values11:42
- Example VII: Find the Critical Values f(x) = cos²(2x) on [0,2π]16:57
- Example VIII: Find the Absolute Max & Min f(x) = 2sinx + 2cos x on [0,(π/3)]20:08
- Example IX: Find the Absolute Max & Min f(x) = (ln(2x)) / x on [1,3]24:39
25m 54s
- Intro0:00
- Rolle's Theorem0:08
- Rolle's Theorem: If & Then0:09
- Rolle's Theorem: Geometrically2:06
- There May Be More than 1 c Such That f'( c ) = 03:30
- Example I: Rolle's Theorem4:58
- The Mean Value Theorem9:12
- The Mean Value Theorem: If & Then9:13
- The Mean Value Theorem: Geometrically11:07
- Example II: Mean Value Theorem13:43
- Example III: Mean Value Theorem21:19
25m 54s
- Intro0:00
- Using Derivatives to Graph Functions, Part I0:12
- Increasing/ Decreasing Test0:13
- Example I: Find the Intervals Over Which the Function is Increasing & Decreasing3:26
- Example II: Find the Local Maxima & Minima of the Function19:18
- Example III: Find the Local Maxima & Minima of the Function31:39
44m 58s
- Intro0:00
- Using Derivatives to Graph Functions, Part II0:13
- Concave Up & Concave Down0:14
- What Does This Mean in Terms of the Derivative?6:14
- Point of Inflection8:52
- Example I: Graph the Function13:18
- Example II: Function x⁴ - 5x²19:03
- Intervals of Increase & Decrease19:04
- Local Maxes and Mins25:01
- Intervals of Concavity & X-Values for the Points of Inflection29:18
- Intervals of Concavity & Y-Values for the Points of Inflection34:18
- Graphing the Function40:52
49m 19s
- Intro0:00
- Example I: Intervals, Local Maxes & Mins0:26
- Example II: Intervals, Local Maxes & Mins5:05
- Example III: Intervals, Local Maxes & Mins, and Inflection Points13:40
- Example IV: Intervals, Local Maxes & Mins, Inflection Points, and Intervals of Concavity23:02
- Example V: Intervals, Local Maxes & Mins, Inflection Points, and Intervals of Concavity34:36
59m 1s
- Intro0:00
- Example I: Intervals, Local Maxes & Mins, Inflection Points, Intervals of Concavity, and Asymptotes0:11
- Example II: Intervals, Local Maxes & Mins, Inflection Points, Intervals of Concavity, and Asymptotes21:24
- Example III: Cubic Equation f(x) = Ax³ + Bx² + Cx + D37:56
- Example IV: Intervals, Local Maxes & Mins, Inflection Points, Intervals of Concavity, and Asymptotes46:19
30m 9s
- Intro0:00
- L'Hospital's Rule0:19
- Indeterminate Forms0:20
- L'Hospital's Rule3:38
- Example I: Evaluate the Following Limit Using L'Hospital's Rule8:50
- Example II: Evaluate the Following Limit Using L'Hospital's Rule10:30
- Indeterminate Products11:54
- Indeterminate Products11:55
- Example III: L'Hospital's Rule & Indeterminate Products13:57
- Indeterminate Differences17:00
- Indeterminate Differences17:01
- Example IV: L'Hospital's Rule & Indeterminate Differences18:57
- Indeterminate Powers22:20
- Indeterminate Powers22:21
- Example V: L'Hospital's Rule & Indeterminate Powers25:13
38m 14s
- Intro0:00
- Example I: Evaluate the Following Limit0:17
- Example II: Evaluate the Following Limit2:45
- Example III: Evaluate the Following Limit6:54
- Example IV: Evaluate the Following Limit8:43
- Example V: Evaluate the Following Limit11:01
- Example VI: Evaluate the Following Limit14:48
- Example VII: Evaluate the Following Limit17:49
- Example VIII: Evaluate the Following Limit20:37
- Example IX: Evaluate the Following Limit25:16
- Example X: Evaluate the Following Limit32:44
49m 59s
- Intro0:00
- Example I: Find the Dimensions of the Box that Gives the Greatest Volume1:23
- Fundamentals of Optimization Problems18:08
- Fundamental #118:33
- Fundamental #219:09
- Fundamental #319:19
- Fundamental #420:59
- Fundamental #521:55
- Fundamental #623:44
- Example II: Demonstrate that of All Rectangles with a Given Perimeter, the One with the Largest Area is a Square24:36
- Example III: Find the Points on the Ellipse 9x² + y² = 9 Farthest Away from the Point (1,0)35:13
- Example IV: Find the Dimensions of the Rectangle of Largest Area that can be Inscribed in a Circle of Given Radius R43:10
55m 10s
- Intro0:00
- Example I: Optimization Problem0:13
- Example II: Optimization Problem17:34
- Example III: Optimization Problem35:06
- Example IV: Revenue, Cost, and Profit43:22
30m 22s
- Intro0:00
- Newton's Method0:45
- Newton's Method0:46
- Example I: Find x2 and x313:18
- Example II: Use Newton's Method to Approximate15:48
- Example III: Find the Root of the Following Equation to 6 Decimal Places19:57
- Example IV: Use Newton's Method to Find the Coordinates of the Inflection Point23:11
55m 26s
- Intro0:00
- Antiderivatives0:23
- Definition of an Antiderivative0:24
- Antiderivative Theorem7:58
- Function & Antiderivative12:10
- x^n12:30
- 1/x13:00
- e^x13:08
- cos x13:18
- sin x14:01
- sec² x14:11
- secxtanx14:18
- 1/√(1-x²)14:26
- 1/(1+x²)14:36
- -1/√(1-x²)14:45
- Example I: Find the Most General Antiderivative for the Following Functions15:07
- Function 1: f(x) = x³ -6x² + 11x - 915:42
- Function 2: f(x) = 14√(x) - 27 4√x19:12
- Function 3: (fx) = cos x - 14 sinx20:53
- Function 4: f(x) = (x⁵+2√x )/( x^(4/3) )22:10
- Function 5: f(x) = (3e^x) - 2/(1+x²)25:42
- Example II: Given the Following, Find the Original Function f(x)26:37
- Function 1: f'(x) = 5x³ - 14x + 24, f(2) = 4027:55
- Function 2: f'(x) 3 sinx + sec²x, f(π/6) = 530:34
- Function 3: f''(x) = 8x - cos x, f(1.5) = 12.7, f'(1.5) = 4.232:54
- Function 4: f''(x) = 5/(√x), f(2) 15, f'(2) = 737:54
- Example III: Falling Object41:58
- Problem 1: Find an Equation for the Height of the Ball after t Seconds42:48
- Problem 2: How Long Will It Take for the Ball to Strike the Ground?48:30
- Problem 3: What is the Velocity of the Ball as it Hits the Ground?49:52
- Problem 4: Initial Velocity of 6 m/s, How Long Does It Take to Reach the Ground?50:46
51m 3s
- Intro0:00
- The Area Under a Curve0:13
- Approximate Using Rectangles0:14
- Let's Do This Again, Using 4 Different Rectangles9:40
- Approximate with Rectangles16:10
- Left Endpoint18:08
- Right Endpoint25:34
- Left Endpoint vs. Right Endpoint30:58
- Number of Rectangles34:08
- True Area37:36
- True Area37:37
- Sigma Notation & Limits43:32
- When You Have to Explicitly Solve Something47:56
33m 7s
- Intro0:00
- Example I: Using Left Endpoint & Right Endpoint to Approximate Area Under a Curve0:10
- Example II: Using 5 Rectangles, Approximate the Area Under the Curve11:32
- Example III: Find the True Area by Evaluating the Limit Expression16:07
- Example IV: Find the True Area by Evaluating the Limit Expression24:52
43m 19s
- Intro0:00
- The Definite Integral0:08
- Definition to Find the Area of a Curve0:09
- Definition of the Definite Integral4:08
- Symbol for Definite Integral8:45
- Regions Below the x-axis15:18
- Associating Definite Integral to a Function19:38
- Integrable Function27:20
- Evaluating the Definite Integral29:26
- Evaluating the Definite Integral29:27
- Properties of the Definite Integral35:24
- Properties of the Definite Integral35:25
32m 14s
- Intro0:00
- Example I: Approximate the Following Definite Integral Using Midpoints & Sub-intervals0:11
- Example II: Express the Following Limit as a Definite Integral5:28
- Example III: Evaluate the Following Definite Integral Using the Definition6:28
- Example IV: Evaluate the Following Integral Using the Definition17:06
- Example V: Evaluate the Following Definite Integral by Using Areas25:41
- Example VI: Definite Integral30:36
24m 17s
- Intro0:00
- The Fundamental Theorem of Calculus0:17
- Evaluating an Integral0:18
- Lim as x → ∞12:19
- Taking the Derivative14:06
- Differentiation & Integration are Inverse Processes15:04
- 1st Fundamental Theorem of Calculus20:08
- 1st Fundamental Theorem of Calculus20:09
- 2nd Fundamental Theorem of Calculus22:30
- 2nd Fundamental Theorem of Calculus22:31
25m 21s
- Intro0:00
- Example I: Find the Derivative of the Following Function0:17
- Example II: Find the Derivative of the Following Function1:40
- Example III: Find the Derivative of the Following Function2:32
- Example IV: Find the Derivative of the Following Function5:55
- Example V: Evaluate the Following Integral7:13
- Example VI: Evaluate the Following Integral9:46
- Example VII: Evaluate the Following Integral12:49
- Example VIII: Evaluate the Following Integral13:53
- Example IX: Evaluate the Following Graph15:24
- Local Maxs and Mins for g(x)15:25
- Where Does g(x) Achieve Its Absolute Max on [0,8]20:54
- On What Intervals is g(x) Concave Up/Down?22:20
- Sketch a Graph of g(x)24:34
34m 22s
- Intro0:00
- Example I: Evaluate the Following Indefinite Integral0:10
- Example II: Evaluate the Following Definite Integral0:59
- Example III: Evaluate the Following Integral2:59
- Example IV: Velocity Function7:46
- Part A: Net Displacement7:47
- Part B: Total Distance Travelled13:15
- Example V: Linear Density Function20:56
- Example VI: Acceleration Function25:10
- Part A: Velocity Function at Time t25:11
- Part B: Total Distance Travelled During the Time Interval28:38
27m 20s
- Intro0:00
- Table of Integrals0:35
- Example I: Evaluate the Following Indefinite Integral2:02
- Example II: Evaluate the Following Indefinite Integral7:27
- Example IIII: Evaluate the Following Indefinite Integral10:57
- Example IV: Evaluate the Following Indefinite Integral12:33
- Example V: Evaluate the Following14:28
- Example VI: Evaluate the Following16:00
- Example VII: Evaluate the Following19:01
- Example VIII: Evaluate the Following21:49
- Example IX: Evaluate the Following24:34
34m 56s
- Intro0:00
- Areas Between Two Curves: Function of x0:08
- Graph 1: Area Between f(x) & g(x)0:09
- Graph 2: Area Between f(x) & g(x)4:07
- Is It Possible to Write as a Single Integral?8:20
- Area Between the Curves on [a,b]9:24
- Absolute Value10:32
- Formula for Areas Between Two Curves: Top Function - Bottom Function17:03
- Areas Between Curves: Function of y17:49
- What if We are Given Functions of y?17:50
- Formula for Areas Between Two Curves: Right Function - Left Function21:48
- Finding a & b22:32
42m 55s
- Intro0:00
- Instructions for the Example Problems0:10
- Example I: y = 7x - x² and y=x0:37
- Example II: x=y²-3, x=e^((1/2)y), y=-1, and y=26:25
- Example III: y=(1/x), y=(1/x³), and x=412:25
- Example IV: 15-2x² and y=x²-515:52
- Example V: x=(1/8)y³ and x=6-y²20:20
- Example VI: y=cos x, y=sin(2x), [0,π/2]24:34
- Example VII: y=2x², y=10x², 7x+2y=1029:51
- Example VIII: Velocity vs. Time33:23
- Part A: At 2.187 Minutes, Which care is Further Ahead?33:24
- Part B: If We Shaded the Region between the Graphs from t=0 to t=2.187, What Would This Shaded Area Represent?36:32
- Part C: At 4 Minutes Which Car is Ahead?37:11
- Part D: At What Time Will the Cars be Side by Side?37:50
34m 15s
- Intro0:00
- Volumes I: Slices0:18
- Rotate the Graph of y=√x about the x-axis0:19
- How can I use Integration to Find the Volume?3:16
- Slice the Solid Like a Loaf of Bread5:06
- Volumes Definition8:56
- Example I: Find the Volume of the Solid Obtained by Rotating the Region Bounded by the Given Functions about the Given Line of Rotation12:18
- Example II: Find the Volume of the Solid Obtained by Rotating the Region Bounded by the Given Functions about the Given Line of Rotation19:05
- Example III: Find the Volume of the Solid Obtained by Rotating the Region Bounded by the Given Functions about the Given Line of Rotation25:28
51m 43s
- Intro0:00
- Volumes II: Volumes by Washers0:11
- Rotating Region Bounded by y=x³ & y=x around the x-axis0:12
- Equation for Volumes by Washer11:14
- Process for Solving Volumes by Washer13:40
- Example I: Find the Volume of the Solid Obtained by Rotating the Region Bounded by the Following Functions around the Given Axis15:58
- Example II: Find the Volume of the Solid Obtained by Rotating the Region Bounded by the Following Functions around the Given Axis25:07
- Example III: Find the Volume of the Solid Obtained by Rotating the Region Bounded by the Following Functions around the Given Axis34:20
- Example IV: Find the Volume of the Solid Obtained by Rotating the Region Bounded by the Following Functions around the Given Axis44:05
49m 36s
- Intro0:00
- Solids That Are Not Solids-of-Revolution0:11
- Cross-Section Area Review0:12
- Cross-Sections That Are Not Solids-of-Revolution7:36
- Example I: Find the Volume of a Pyramid Whose Base is a Square of Side-length S, and Whose Height is H10:54
- Example II: Find the Volume of a Solid Whose Cross-sectional Areas Perpendicular to the Base are Equilateral Triangles20:39
- Example III: Find the Volume of a Pyramid Whose Base is an Equilateral Triangle of Side-Length A, and Whose Height is H29:27
- Example IV: Find the Volume of a Solid Whose Base is Given by the Equation 16x² + 4y² = 6436:47
- Example V: Find the Volume of a Solid Whose Base is the Region Bounded by the Functions y=3-x² and the x-axis46:13
50m 2s
- Intro0:00
- Volumes by Cylindrical Shells0:11
- Find the Volume of the Following Region0:12
- Volumes by Cylindrical Shells: Integrating Along x14:12
- Volumes by Cylindrical Shells: Integrating Along y14:40
- Volumes by Cylindrical Shells Formulas16:22
- Example I: Using the Method of Cylindrical Shells, Find the Volume of the Solid18:33
- Example II: Using the Method of Cylindrical Shells, Find the Volume of the Solid25:57
- Example III: Using the Method of Cylindrical Shells, Find the Volume of the Solid31:38
- Example IV: Using the Method of Cylindrical Shells, Find the Volume of the Solid38:44
- Example V: Using the Method of Cylindrical Shells, Find the Volume of the Solid44:03
32m 13s
- Intro0:00
- The Average Value of a Function0:07
- Average Value of f(x)0:08
- What if The Domain of f(x) is Not Finite?2:23
- Let's Calculate Average Value for f(x) = x² [2,5]4:46
- Mean Value Theorem for Integrate9:25
- Example I: Find the Average Value of the Given Function Over the Given Interval14:06
- Example II: Find the Average Value of the Given Function Over the Given Interval18:25
- Example III: Find the Number A Such that the Average Value of the Function f(x) = -4x² + 8x + 4 Equals 2 Over the Interval [-1,A]24:04
- Example IV: Find the Average Density of a Rod27:47
50m 32s
- Intro0:00
- Integration by Parts0:08
- The Product Rule for Differentiation0:09
- Integrating Both Sides Retains the Equality0:52
- Differential Notation2:24
- Example I: ∫ x cos x dx5:41
- Example II: ∫ x² sin(2x)dx12:01
- Example III: ∫ (e^x) cos x dx18:19
- Example IV: ∫ (sin^-1) (x) dx23:42
- Example V: ∫₁⁵ (lnx)² dx28:25
- Summary32:31
- Tabular Integration35:08
- Case 135:52
- Example: ∫x³sinx dx36:39
- Case 240:28
- Example: ∫e^(2x) sin 3x41:14
24m 50s
- Intro0:00
- Example I: ∫ sin³ (x) dx1:36
- Example II: ∫ cos⁵(x)sin²(x)dx4:36
- Example III: ∫ sin⁴(x)dx9:23
- Summary for Evaluating Trigonometric Integrals of the Following Type: ∫ (sin^m) (x) (cos^p) (x) dx15:59
- #1: Power of sin is Odd16:00
- #2: Power of cos is Odd16:41
- #3: Powers of Both sin and cos are Odd16:55
- #4: Powers of Both sin and cos are Even17:10
- Example IV: ∫ tan⁴ (x) sec⁴ (x) dx17:34
- Example V: ∫ sec⁹(x) tan³(x) dx20:55
- Summary for Evaluating Trigonometric Integrals of the Following Type: ∫ (sec^m) (x) (tan^p) (x) dx23:31
- #1: Power of sec is Odd23:32
- #2: Power of tan is Odd24:04
- #3: Powers of sec is Odd and/or Power of tan is Even24:18
22m 12s
- Intro0:00
- Trigonometric Integrals II0:09
- Recall: ∫tanx dx0:10
- Let's Find ∫secx dx3:23
- Example I: ∫ tan⁵ (x) dx6:23
- Example II: ∫ sec⁵ (x) dx11:41
- Summary: How to Deal with Integrals of Different Types19:04
- Identities to Deal with Integrals of Different Types19:05
- Example III: ∫cos(5x)sin(9x)dx19:57
17m 22s
- Intro0:00
- Example I: ∫sin²(x)cos⁷(x)dx0:14
- Example II: ∫x sin²(x) dx3:56
- Example III: ∫csc⁴ (x/5)dx8:39
- Example IV: ∫( (1-tan²x)/(sec²x) ) dx11:17
- Example V: ∫ 1 / (sinx-1) dx13:19
55m 12s
- Intro0:00
- Integration by Partial Fractions I0:11
- Recall the Idea of Finding a Common Denominator0:12
- Decomposing a Rational Function to Its Partial Fractions4:10
- 2 Types of Rational Function: Improper & Proper5:16
- Improper Rational Function7:26
- Improper Rational Function7:27
- Proper Rational Function11:16
- Proper Rational Function & Partial Fractions11:17
- Linear Factors14:04
- Irreducible Quadratic Factors15:02
- Case 1: G(x) is a Product of Distinct Linear Factors17:10
- Example I: Integration by Partial Fractions20:33
- Case 2: D(x) is a Product of Linear Factors40:58
- Example II: Integration by Partial Fractions44:41
42m 57s
- Intro0:00
- Case 3: D(x) Contains Irreducible Factors0:09
- Example I: Integration by Partial Fractions5:19
- Example II: Integration by Partial Fractions16:22
- Case 4: D(x) has Repeated Irreducible Quadratic Factors27:30
- Example III: Integration by Partial Fractions30:19
46m 37s
- Intro0:00
- Introduction to Differential Equations0:09
- Overview0:10
- Differential Equations Involving Derivatives of y(x)2:08
- Differential Equations Involving Derivatives of y(x) and Function of y(x)3:23
- Equations for an Unknown Number6:28
- What are These Differential Equations Saying?10:30
- Verifying that a Function is a Solution of the Differential Equation13:00
- Verifying that a Function is a Solution of the Differential Equation13:01
- Verify that y(x) = 4e^x + 3x² + 6x + e^π is a Solution of this Differential Equation17:20
- General Solution22:00
- Particular Solution24:36
- Initial Value Problem27:42
- Example I: Verify that a Family of Functions is a Solution of the Differential Equation32:24
- Example II: For What Values of K Does the Function Satisfy the Differential Equation36:07
- Example III: Verify the Solution and Solve the Initial Value Problem39:47
28m 8s
- Intro0:00
- Separation of Variables0:28
- Separation of Variables0:29
- Example I: Solve the Following g Initial Value Problem8:29
- Example II: Solve the Following g Initial Value Problem13:46
- Example III: Find an Equation of the Curve18:48
51m 7s
- Intro0:00
- Standard Growth Model0:30
- Definition of the Standard/Natural Growth Model0:31
- Initial Conditions8:00
- The General Solution9:16
- Example I: Standard Growth Model10:45
- Logistic Growth Model18:33
- Logistic Growth Model18:34
- Solving the Initial Value Problem25:21
- What Happens When t → ∞36:42
- Example II: Solve the Following g Initial Value Problem41:50
- Relative Growth Rate46:56
- Relative Growth Rate46:57
- Relative Growth Rate Version for the Standard model49:04
24m 37s
- Intro0:00
- Slope Fields0:35
- Slope Fields0:36
- Graphing the Slope Fields, Part 111:12
- Graphing the Slope Fields, Part 215:37
- Graphing the Slope Fields, Part 317:25
- Steps to Solving Slope Field Problems20:24
- Example I: Draw or Generate the Slope Field of the Differential Equation y'=x cos y22:38
45m 29s
- Intro0:00
- Exam Link0:10
- Problem #11:26
- Problem #22:52
- Problem #34:42
- Problem #47:03
- Problem #510:01
- Problem #613:49
- Problem #715:16
- Problem #819:06
- Problem #923:10
- Problem #1028:10
- Problem #1131:30
- Problem #1233:53
- Problem #1337:45
- Problem #1441:17
41m 55s
- Intro0:00
- Problem #150:22
- Problem #163:10
- Problem #175:30
- Problem #188:03
- Problem #199:53
- Problem #2014:51
- Problem #2117:30
- Problem #2222:12
- Problem #2325:48
- Problem #2429:57
- Problem #2533:35
- Problem #2635:57
- Problem #2737:57
- Problem #2840:04
58m 47s
- Intro0:00
- Problem #11:22
- Problem #24:55
- Problem #310:49
- Problem #413:05
- Problem #514:54
- Problem #617:25
- Problem #718:39
- Problem #820:27
- Problem #926:48
- Problem #1028:23
- Problem #1134:03
- Problem #1236:25
- Problem #1339:52
- Problem #1443:12
- Problem #1547:18
- Problem #1650:41
- Problem #1756:38
25m 40s
- Intro0:00
- Problem #1: Part A1:14
- Problem #1: Part B4:46
- Problem #1: Part C8:00
- Problem #2: Part A12:24
- Problem #2: Part B16:51
- Problem #2: Part C17:17
- Problem #3: Part A18:16
- Problem #3: Part B19:54
- Problem #3: Part C21:44
- Problem #3: Part D22:57
31m 20s
- Intro0:00
- Problem #4: Part A1:35
- Problem #4: Part B5:54
- Problem #4: Part C8:50
- Problem #4: Part D9:40
- Problem #5: Part A11:26
- Problem #5: Part B13:11
- Problem #5: Part C15:07
- Problem #5: Part D19:57
- Problem #6: Part A22:01
- Problem #6: Part B25:34
- Problem #6: Part C28:54
2 answers
Last reply by: Tewodros Belachew
Sun Dec 17, 2017 8:18 PM
Post by Tewodros Belachew on December 13, 2017
Hello professor,
I have a question on the first topic "Limit as X goes to infinity. Around 7:00 you said as x goes to positive infinity the denominator gets really big , I'm confused on how you figure that out with out solving it? and you also said as the denominator gets huge , 1/x-3 gets very small, how does that fraction get small and the denominator gets huge when x-3 is the denominator ? what is the "denominator" you're preferring to? I'm having difficulties understanding this topic. I have no back ground of learning calculus and my school said I have to take Ap calculus so It's kind of difficult for me to understand it, I would really appreciate it if you recommend me books, websites, or things to do to understand Ap calculus.
Sincerely,
Betty
1 answer
Wed Oct 4, 2017 2:50 AM
Post by Maya Balaji on October 1, 2017
Hello professor,
For example IV, it was said that as x goes to 0, 1/x becomes positive infinity, however for all the previous examples, we noted that 0 cannot be in the denominator, and if it is, we must manipulate the function. Why is this treated differently, and how can I recognize when to use each method?
Thank you,
Maya.
0 answers
Post by Maya Balaji on October 1, 2017
Hello! For the lim as x--> infinity of some function: Must we take the limit as x goes to - infinity and + infinity: and if so, does this correspond to taking the right and left-hand limits?
If x goes to infinity, why does -infinity correspond to the left hand limit? I thought that we were just looking left and right of positive infinity, and negative infinity is in the completely opposite direction.
Thank you,
Maya.
1 answer
Fri Mar 25, 2016 11:09 PM
Post by Acme Wang on March 8, 2016
Hi Professor Hovasapian,
I wanna ask some questions in Example III. The limit as x approaches positive infinity doesn't equal the limit as x approaches negative infinity, so can I say the limit for the equation does not exist? Kind of mixed up with the left-handed and right-handed limit.
Also, when x approaches infinity, does that indicate I must consider two circumstances (x approaches positive infinity and negative infinity)? Even when I take my AP exam?
Besides, in example III when x approaches positive infinity, you then wrote x>0? Why not x>1? Does xà+? means x>0?
Sincerely,
Acme