Section 1: First-Order Equations |
|
Linear Equations |
1:07:21 |
| |
Intro |
0:00 | |
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Lesson Objectives |
0:19 | |
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How to Solve Linear Equations |
2:54 | |
| |
| Calculate the Integrating Factor |
2:58 | |
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| Changes the Left Side so We Can Integrate Both Sides |
3:27 | |
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| Solving Linear Equations |
5:32 | |
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Further Notes |
6:10 | |
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| If P(x) is Negative |
6:26 | |
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| Leave Off the Constant |
9:38 | |
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| The C Is Important When Integrating Both Sides of the Equation |
9:55 | |
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Example 1 |
10:29 | |
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Example 2 |
22:56 | |
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Example 3 |
36:12 | |
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Example 4 |
39:24 | |
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Example 5 |
44:10 | |
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Example 6 |
56:42 | |
|
Separable Equations |
35:11 |
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Intro |
0:00 | |
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Lesson Objectives |
0:19 | |
| |
| Some Equations Are Both Linear and Separable So You Can Use Either Technique to Solve Them |
1:33 | |
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| Important to Add C When You Do the Integration |
2:27 | |
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Example 1 |
4:28 | |
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Example 2 |
10:45 | |
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Example 3 |
14:43 | |
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Example 4 |
19:21 | |
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Example 5 |
27:23 | |
|
Slope & Direction Fields |
1:11:36 |
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Intro |
0:00 | |
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Lesson Objectives |
0:20 | |
| |
| If You Can Manipulate a Differential Equation Into a Certain Form, You Can Draw a Slope Field Also Known as a Direction Field |
0:23 | |
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| How You Do This |
0:45 | |
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Solution Trajectories |
2:49 | |
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| Never Cross Each Other |
3:44 | |
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| General Solution to the Differential Equation |
4:03 | |
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| Use an Initial Condition to Find Which Solution Trajectory You Want |
4:59 | |
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Example 1 |
6:52 | |
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Example 2 |
14:20 | |
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Example 3 |
26:36 | |
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Example 4 |
34:21 | |
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Example 5 |
46:09 | |
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Example 6 |
59:51 | |
|
Applications, Modeling, & Word Problems of First-Order Equations |
1:05:19 |
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Intro |
0:00 | |
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Lesson Overview |
0:38 | |
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| Mixing |
1:00 | |
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| Population |
2:49 | |
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| Finance |
3:22 | |
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| Set Variables |
4:39 | |
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| Write Differential Equation |
6:29 | |
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| Solve It |
10:54 | |
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| Answer Questions |
11:47 | |
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Example 1 |
13:29 | |
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Example 2 |
24:53 | |
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Example 3 |
32:13 | |
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Example 4 |
42:46 | |
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Example 5 |
55:05 | |
|
Autonomous Equations & Phase Plane Analysis |
1:01:20 |
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Intro |
0:00 | |
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Lesson Overview |
0:18 | |
| |
| Autonomous Differential Equations Have the Form y' = f(x) |
0:21 | |
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| Phase Plane Analysis |
0:48 | |
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| y' < 0 |
2:56 | |
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| y' > 0 |
3:04 | |
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| If we Perturb the Equilibrium Solutions |
5:51 | |
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| Equilibrium Solutions |
7:44 | |
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| Solutions Will Return to Stable Equilibria |
8:06 | |
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| Solutions Will Tend Away From Unstable Equilibria |
9:32 | |
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| Semistable Equilibria |
10:59 | |
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Example 1 |
11:43 | |
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Example 2 |
15:50 | |
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Example 3 |
28:27 | |
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Example 4 |
31:35 | |
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Example 5 |
43:03 | |
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Example 6 |
49:01 | |
Section 2: Second-Order Equations |
|
Distinct Roots of Second Order Equations |
28:44 |
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Intro |
0:00 | |
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Lesson Overview |
0:36 | |
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| Linear Means |
0:50 | |
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| Second-Order |
1:15 | |
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| Homogeneous |
1:30 | |
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| Constant Coefficient |
1:55 | |
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| Solve the Characteristic Equation |
2:33 | |
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| Roots r1 and r2 |
3:43 | |
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| To Find c1 and c2, Use Initial Conditions |
4:50 | |
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Example 1 |
5:46 | |
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Example 2 |
8:20 | |
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Example 3 |
16:20 | |
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Example 4 |
18:26 | |
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Example 5 |
23:52 | |
|
Complex Roots of Second Order Equations |
31:49 |
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Intro |
0:00 | |
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Lesson Overview |
0:15 | |
| |
| Sometimes The Characteristic Equation Has Complex Roots |
1:12 | |
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Example 1 |
3:21 | |
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Example 2 |
7:42 | |
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Example 3 |
15:25 | |
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Example 4 |
18:59 | |
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Example 5 |
27:52 | |
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Repeated Roots & Reduction of Order |
43:02 |
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Intro |
0:00 | |
| |
Lesson Overview |
0:23 | |
| |
| If the Characteristic Equation Has a Double Root |
1:46 | |
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| Reduction of Order |
3:10 | |
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Example 1 |
7:23 | |
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Example 2 |
9:20 | |
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Example 3 |
14:12 | |
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Example 4 |
31:49 | |
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Example 5 |
33:21 | |
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Undetermined Coefficients of Inhomogeneous Equations |
50:01 |
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Intro |
0:00 | |
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Lesson Overview |
0:11 | |
| |
| Inhomogeneous Equation Means the Right Hand Side is Not 0 Anymore |
0:21 | |
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| First Solve the Homogeneous Equation |
1:04 | |
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| Find a Particular Solution to the Inhomogeneous Equation Using Undetermined Coefficients |
2:03 | |
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| g(t) vs. Guess for ypar |
2:42 | |
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| If Any Term of Your Guess for ypar Looks Like Any Term of yhom |
5:07 | |
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Example 1 |
7:54 | |
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Example 2 |
15:25 | |
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Example 3 |
23:45 | |
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Example 4 |
33:35 | |
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Example 5 |
42:57 | |
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Inhomogeneous Equations: Variation of Parameters |
49:22 |
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Intro |
0:00 | |
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Lesson Overview |
0:31 | |
| |
| Inhomogeneous vs. Homogeneous |
0:47 | |
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| First Solve the Homogeneous Equation |
1:17 | |
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| Notice There is No Coefficient in Front of y'' |
1:27 | |
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| Find a Particular Solution to the Inhomogeneous Equation Using Variation of Parameters |
2:32 | |
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| How to Solve |
4:33 | |
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| Hint on Solving the System |
5:23 | |
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Example 1 |
7:27 | |
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Example 2 |
17:46 | |
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Example 3 |
23:14 | |
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Example 4 |
31:49 | |
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Example 5 |
36:00 | |
Section 3: Series Solutions |
|
Review of Power Series |
57:38 |
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Intro |
0:00 | |
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Lesson Overview |
0:36 | |
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| Taylor Series Expansion |
0:37 | |
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| Maclaurin Series |
2:36 | |
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| Common Maclaurin Series to Remember From Calculus |
3:35 | |
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| Radius of Convergence |
7:58 | |
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| Ratio Test |
12:05 | |
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Example 1 |
15:18 | |
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Example 2 |
20:02 | |
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Example 3 |
27:32 | |
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Example 4 |
39:33 | |
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Example 5 |
45:42 | |
|
Series Solutions Near an Ordinary Point |
1:20:28 |
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Intro |
0:00 | |
| |
Lesson Overview |
0:49 | |
| |
| Guess a Power Series Solution and Calculate Its Derivatives, Example 1 |
1:03 | |
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| Guess a Power Series Solution and Calculate Its Derivatives, Example 2 |
3:14 | |
| |
| Combine the Series |
5:00 | |
| |
| Match Exponents on x By Shifting Indices |
5:11 | |
| |
| Match Starting Indices By Pulling Out Initial Terms |
5:51 | |
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| Find a Recurrence Relation on the Coefficients |
7:09 | |
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Example 1 |
7:46 | |
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Example 2 |
19:10 | |
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Example 3 |
29:57 | |
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Example 4 |
41:46 | |
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Example 5 |
57:23 | |
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Example 6 |
69:12 | |
|
Euler Equations |
24:42 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
0:11 | |
| |
| Euler Equation |
0:15 | |
| |
| Real, Distinct Roots |
2:22 | |
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| Real, Repeated Roots |
2:37 | |
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| Complex Roots |
2:49 | |
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Example 1 |
3:51 | |
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Example 2 |
6:20 | |
| |
Example 3 |
8:27 | |
| |
Example 4 |
13:04 | |
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Example 5 |
15:31 | |
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Example 6 |
18:31 | |
|
Series Solutions |
1:26:17 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
0:13 | |
| |
| Singular Point |
1:17 | |
| |
Definition: Pole of Order n |
1:58 | |
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| Pole Of Order n |
2:04 | |
| |
| Regular Singular Point |
3:25 | |
| |
Solving Around Regular Singular Points |
7:08 | |
| |
| Indical Equation |
7:30 | |
| |
| If the Difference Between the Roots is An Integer |
8:06 | |
| |
| If the Difference Between the Roots is Not An Integer |
8:29 | |
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Example 1 |
8:47 | |
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Example 2 |
14:57 | |
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Example 3 |
25:40 | |
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Example 4 |
47:23 | |
| |
Example 5 |
69:01 | |
Section 4: Laplace Transform |
|
Laplace Transforms |
41:52 |
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Intro |
0:00 | |
| |
Lesson Overview |
0:09 | |
| |
| Laplace Transform of a Function f(t) |
0:18 | |
| |
| Laplace Transform is Linear |
1:04 | |
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Example 1 |
1:43 | |
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Example 2 |
18:30 | |
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Example 3 |
22:06 | |
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Example 4 |
28:27 | |
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Example 5 |
33:54 | |
|
Inverse Laplace Transforms |
47:05 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
0:09 | |
| |
| Laplace Transform L{f} |
0:13 | |
| |
| Run Partial Fractions |
0:24 | |
| |
Common Laplace Transforms |
1:20 | |
| |
Example 1 |
3:24 | |
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Example 2 |
9:55 | |
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Example 3 |
14:49 | |
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Example 4 |
22:03 | |
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Example 5 |
33:51 | |
|
Laplace Transform Initial Value Problems |
45:15 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
0:12 | |
| |
| Start With Initial Value Problem |
0:14 | |
| |
| Take the Laplace Transform of Both Sides of the Differential Equation |
0:37 | |
| |
| Plug in the Identities |
1:20 | |
| |
| Take the Inverse Laplace Transform to Find y |
2:40 | |
| |
| Example 1 |
4:15 | |
| |
| Example 2 |
11:30 | |
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| Example 3 |
17:59 | |
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| Example 4 |
24:51 | |
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| Example 5 |
36:05 | |
Section 5: Review of Linear Algebra |
|
Review of Linear Algebra |
57:30 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
0:41 | |
| |
| Matrix |
0:54 | |
| |
| Determinants |
4:45 | |
| |
3x3 Determinants |
5:08 | |
| |
Eigenvalues and Eigenvectors |
7:01 | |
| |
| Eigenvector |
7:48 | |
| |
| Eigenvalue |
7:54 | |
| |
Lesson Overview |
8:17 | |
| |
| Characteristic Polynomial |
8:47 | |
| |
| Find Corresponding Eigenvector |
9:03 | |
| |
Example 1 |
10:19 | |
| |
Example 2 |
16:49 | |
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Example 3 |
20:52 | |
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Example 4 |
25:34 | |
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Example 5 |
35:05 | |
Section 6: Systems of Equations |
|
Distinct Real Eigenvalues |
59:26 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
1:11 | |
| |
How to Solve Systems |
2:48 | |
| |
| Find the Eigenvalues and Their Corresponding Eigenvectors |
2:50 | |
| |
| General Solution |
4:30 | |
| |
| Use Initial Conditions to Find c1 and c2 |
4:57 | |
| |
Graphing the Solutions |
5:20 | |
| |
| Solution Trajectories Tend Towards 0 or ∞ Depending on Whether r1 or r2 are Positive or Negative |
6:35 | |
| |
| Solution Trajectories Tend Towards the Axis Spanned by the Eigenvector Corresponding to the Larger Eigenvalue |
7:27 | |
| |
Example 1 |
9:05 | |
| |
Example 2 |
21:06 | |
| |
Example 3 |
26:38 | |
| |
Example 4 |
36:40 | |
| |
Example 5 |
43:26 | |
| |
Example 6 |
51:33 | |
|
Complex Eigenvalues |
1:03:54 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
0:47 | |
| |
| Recall That to Solve the System of Linear Differential Equations, We find the Eigenvalues and Eigenvectors |
0:52 | |
| |
| If the Eigenvalues are Complex, Then They Will Occur in Conjugate Pairs |
1:13 | |
| |
Expanding Complex Solutions |
2:55 | |
| |
| Euler's Formula |
2:56 | |
| |
| Multiply This Into the Eigenvector, and Separate Into Real and Imaginary Parts |
1:18 | |
| |
Graphing Solutions From Complex Eigenvalues |
5:34 | |
| |
Example 1 |
9:03 | |
| |
Example 2 |
20:48 | |
| |
Example 3 |
28:34 | |
| |
Example 4 |
41:28 | |
| |
Example 5 |
51:21 | |
|
Repeated Eigenvalues |
45:17 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
0:44 | |
| |
| If the Characteristic Equation Has a Repeated Root, Then We First Find the Corresponding Eigenvector |
1:14 | |
| |
| Find the Generalized Eigenvector |
1:25 | |
| |
Solutions from Repeated Eigenvalues |
2:22 | |
| |
| Form the Two Principal Solutions and the Two General Solution |
2:23 | |
| |
| Use Initial Conditions to Solve for c1 and c2 |
3:41 | |
| |
Graphing the Solutions |
3:53 | |
| |
Example 1 |
8:10 | |
| |
Example 2 |
16:24 | |
| |
Example 3 |
23:25 | |
| |
Example 4 |
31:04 | |
| |
Example 5 |
38:17 | |
Section 7: Inhomogeneous Systems |
|
Undetermined Coefficients for Inhomogeneous Systems |
43:37 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
0:35 | |
| |
| First Solve the Corresponding Homogeneous System x'=Ax |
0:37 | |
| |
Solving the Inhomogeneous System |
2:32 | |
| |
| Look for a Single Particular Solution xpar to the Inhomogeneous System |
2:36 | |
| |
| Plug the Guess Into the System and Solve for the Coefficients |
3:27 | |
| |
| Add the Homogeneous Solution and the Particular Solution to Get the General Solution |
3:52 | |
| |
Example 1 |
4:49 | |
| |
Example 2 |
9:30 | |
| |
Example 3 |
15:54 | |
| |
Example 4 |
20:39 | |
| |
Example 5 |
29:43 | |
| |
Example 6 |
37:41 | |
|
Variation of Parameters for Inhomogeneous Systems |
1:08:12 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
0:37 | |
| |
| Find Two Solutions to the Homogeneous System |
2:04 | |
| |
| Look for a Single Particular Solution xpar to the inhomogeneous system as follows |
2:59 | |
| |
Solutions by Variation of Parameters |
3:35 | |
| |
General Solution and Matrix Inversion |
6:35 | |
| |
| General Solution |
6:41 | |
| |
| Hint for Finding Ψ-1 |
6:58 | |
| |
Example 1 |
8:13 | |
| |
Example 2 |
16:23 | |
| |
Example 3 |
32:23 | |
| |
Example 4 |
37:34 | |
| |
Example 5 |
49:00 | |
Section 8: Numerical Techniques |
|
Euler's Method |
45:30 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
0:32 | |
| |
| Euler's Method is a Way to Find Numerical Approximations for Initial Value Problems That We Cannot Solve Analytically |
0:34 | |
| |
| Based on Drawing Lines Along Slopes in a Direction Field |
1:18 | |
| |
Formulas for Euler's Method |
1:57 | |
| |
Example 1 |
4:47 | |
| |
Example 2 |
14:45 | |
| |
Example 3 |
24:03 | |
| |
Example 4 |
33:01 | |
| |
Example 5 |
37:55 | |
|
Runge-Kutta & The Improved Euler Method |
41:04 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
0:43 | |
| |
| Runge-Kutta is Know as the Improved Euler Method |
0:46 | |
| |
| More Sophisticated Than Euler's Method |
1:09 | |
| |
| It is the Fundamental Algorithm Used in Most Professional Software to Solve Differential Equations |
1:16 | |
| |
| Order 2 Runge-Kutta Algorithm |
1:45 | |
| |
Runge-Kutta Order 2 Algorithm |
2:09 | |
| |
Example 1 |
4:57 | |
| |
Example 2 |
10:57 | |
| |
Example 3 |
19:45 | |
| |
Example 4 |
24:35 | |
| |
Example 5 |
31:39 | |
Section 9: Partial Differential Equations |
|
Review of Partial Derivatives |
38:22 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
1:04 | |
| |
| Partial Derivative of u with respect to x |
1:37 | |
| |
| Geometrically, ux Represents the Slope As You Walk in the x-direction on the Surface |
2:47 | |
| |
Computing Partial Derivatives |
3:46 | |
| |
| Algebraically, to Find ux You Treat The Other Variable t as a Constant and Take the Derivative with Respect to x |
3:49 | |
| |
| Second Partial Derivatives |
4:16 | |
| |
| Clairaut's Theorem Says that the Two 'Mixed Partials' Are Always Equal |
5:21 | |
| |
Example 1 |
5:34 | |
| |
Example 2 |
7:40 | |
| |
Example 3 |
11:17 | |
| |
Example 4 |
14:23 | |
| |
Example 5 |
31:55 | |
|
The Heat Equation |
44:40 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
0:28 | |
| |
| Partial Differential Equation |
0:33 | |
| |
| Most Common Ones |
1:17 | |
| |
| Boundary Value Problem |
1:41 | |
| |
Common Partial Differential Equations |
3:41 | |
| |
| Heat Equation |
4:04 | |
| |
| Wave Equation |
5:44 | |
| |
| Laplace's Equation |
7:50 | |
| |
Example 1 |
8:35 | |
| |
Example 2 |
14:21 | |
| |
Example 3 |
21:04 | |
| |
Example 4 |
25:54 | |
| |
Example 5 |
35:12 | |
|
Separation of Variables |
57:44 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
0:26 | |
| |
| Separation of Variables is a Technique for Solving Some Partial Differential Equations |
0:29 | |
| |
Separation of Variables |
2:35 | |
| |
| Try to Separate the Variables |
2:38 | |
| |
| If You Can, Then Both Sides Must Be Constant |
2:52 | |
| |
| Reorganize These Intro Two Ordinary Differential Equations |
3:05 | |
| |
Example 1 |
4:41 | |
| |
Example 2 |
11:06 | |
| |
Example 3 |
18:30 | |
| |
Example 4 |
25:49 | |
| |
Example 5 |
32:53 | |
|
Fourier Series |
1:24:33 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
0:38 | |
| |
| Fourier Series |
0:42 | |
| |
| Find the Fourier Coefficients by the Formulas |
2:05 | |
| |
Notes on Fourier Series |
3:34 | |
| |
| Formula Simplifies |
3:35 | |
| |
| Function Must be Periodic |
4:23 | |
| |
Even and Odd Functions |
5:37 | |
| |
| Definition |
5:45 | |
| |
| Examples |
6:03 | |
| |
Even and Odd Functions and Fourier Series |
9:47 | |
| |
| If f is Even |
9:52 | |
| |
| If f is Odd |
11:29 | |
| |
Extending Functions |
12:46 | |
| |
| If We Want a Cosine Series |
14:13 | |
| |
| If We Wants a Sine Series |
15:20 | |
| |
Example 1 |
17:39 | |
| |
Example 2 |
43:23 | |
| |
Example 3 |
51:14 | |
| |
Example 4 |
61:52 | |
| |
Example 5 |
71:53 | |
|
Solution of the Heat Equation |
47:41 |
| |
Intro |
0:00 | |
| |
Lesson Overview |
0:22 | |
| |
Solving the Heat Equation |
1:03 | |
| |
Procedure for the Heat Equation |
3:29 | |
| |
| Extend So That its Fourier Series Will Have Only Sines |
3:57 | |
| |
| Find the Fourier Series for f(x) |
4:19 | |
| |
Example 1 |
5:21 | |
| |
Example 2 |
8:08 | |
| |
Example 3 |
17:42 | |
| |
Example 4 |
25:13 | |
| |
Example 5 |
28:53 | |
| |
Example 6 |
42:22 | |