Hi Professor Raffi. I am a student self studying for the AP Calculus AB exam in May 2016, and I just wanted to thank you for your great videos. They really explain the concepts well and give me confidence to study for this exam in the comfort of my home.

I was wondering if you have any advice as to how I could best study for AP Calc. I am hoping to get through the AB course really soon (I have graduated from high school and am just taking this course to prepare for university level calculus). I do have a lot of time on my hands so I am only focusing on AP Calc. Do you think it is a good idea to progress to AP Calculus BC if I manage to complete the AB course in the next month? Thanks very much.

Dear Professor William Murry,
Thank you so much for providing an amazing mathematics courses. I was very weak in differential equation and in probability and I have solved all my problems through your courses. I will always remember you in my prayers! Dear Professor, I have one question to you. If you provide a real analysis course through educator.com, it would be very nice of you. As I know you are connoisseur in the field of mathematics, at least you would guide me in real analysis course. As for me, I am doing my M.Phil in economic policy. I am keen to learn the game theory, so for game theory is concerned, it is all about real analysis and optimization. I am good in optimization, but very poor in real analysis. I am looking forward to hear from you soon.
Cordially,
Assad
Turkey

Dr. Eaton I am so blessed to study with your lectures !!!
For real, you are the best science/biology teacher overall my high school experience!!!
Thank you so much.

Dear Mr Phillips just to make it absolutely crystal clear in my mind if, for example in a haploid gamete I have chromosome 1a all thst it contains are alleles?
Now if I take another haploid cell containing chromosome 1b that contains the same allele or an alternative allele, these two haploid cells come together to produce an offspring, will those two alleles produce a gene?
Do you get just half your alleles from one parent and the other half from your other parent and then those alleles produce your genes?
If this is correct then thank you so much, because I have spent quite a while trying to find this answer.
Thank you so much Doctor Philips you are a superb teacher

great teaching professor. I have learned so much from your videos. I cannot thank you enough. I have a question. Starting at 17:30 on this video you saying that you see 2,6,and 4 at the denominator, but all I see is 2,6(3*2=6) and 24(3*8=24)am a little bit confuse as where do you see the 4. Once again thanks.

you are the best.You made chemistry much easier for me.Thank you so much

Nice Lecture Sir! It helped me study for my test! AND I GOT 100!!! Thank you so much!

I know you have heard this before, but I have to say it again....
YOU ARE AMAZING PROFESSOR!!!!!!! educator has great teachers, but you are THE BEST!!!! Thank you for helping me understand the subject. By the way, I love your hair ;) please let it grow out, makes you look like a young Einstein.

I FEEL BAD I DID NOT PURCHASE EDUCATOR.COM IN THE BEGINING OF THE SEMESTER BUT I THINK YOU ARE SUCH A GREAT WONDERFUL HELP. THANK YOU SO MUCH.

These lectures are amazing, they make everything so clear and easy to understand!
Thank you so much!

This is really great, you guys are the best.
I like how he solves practical examples after illustrating the physical concepts of the lesson.

Mr. Hovasapian, you really make me excited to learn chemistry. Your clear understanding of the topics comes through in your clear teaching as well. Thanks so much for your videos!

you're the best teacher ever. Helped me a lot with my college writing! Thank you. And by the way, you are way better than a typical college professor.

you are the best, you and educator really saved me from a big nightmare

thank you! I understood SO MUCH better than what my teacher taught me.... :)

Your lectures are extremely helpful. Thank you so much!
~Natasha

you are the best.You made chemistry much easier for me.Thank you so much

Never mind I hastened you corrected already. you are the greatest math teacher I have seen so far.

master ,I am studying college level and you are the best chemistry master I ever saw in my life time up to this point, your logical way of explaining is really nice sir, thank you for sharing your lectures with educator.com , I only specially sign up for educator.com because by seeing some of your sample lectures. thank you very much sir, I simply enjoy your biochemistry course

You are great teacher and this is the first time that I enjoy every ORG Chem lesson!! Now I can remember CTI because it's always come with sound ding ding ding!!!!! lol Thank you so much!! Is it possible to add some lessons about biological molecules like proteins, amino acids, carbohydrates and lipids?

45 and going back to school next month...Educator is going to be a great help!! Thanks!!

WOW!! YOU JUST SAVED ME ON MY EXAM!!!!!!!! THANK YOU SO MUCH

educator.com has the best professors.

You're an amazing teacher. If ever I miss a class I come watch your videos. You make organic chemistry so simple.

Thank you so much

Paula

Professor Raffi, I have been watching your videos since I started chemistry last fall and they are simply excellent!! I would also like to add that I received a B+ in my first 200 level chemistry course, through distance ed, and i believe your lectures have a great deal to do with that!! Only 4 more chemistry courses to go.... So again, thank you so much!!

Hello Prof. Hovasapian
Thank you so much for your detailed videos which explain some difficult concepts very thoroughly. Your videos helped me go from a C to an A+ on my Chemistry tests! Currently, I am taking Honors Chemistry, which is a weighted course and is very rigorous but does not cover some concepts from AP Chemistry. My school does not offer AP Chemistry but I would still like to take the exam in May. Do you have any suggestions for how I can self-study? Also, do sig figs matter in the AP Chem test? My teacher takes points off our tests if we do not use the correct number of sig figs.

Hi Professor Hovasapian,

I'm Alina from China. Just want to go back here to say Thank You. I've got a 5 on my AP chemistry, and your lectures are basically all my preparation materials. Thank you so much for your dedicated  lectures! They are great lectures for students (including me) who desperately want to learn under a situation that no one around them is familiar with the subject.



Wish you all the best,
Alina

Dear Dr Rafi,

Thank you Dr Rafi and yes there is no doubt that you are the best because of your videos I am doing very well In my Biochemistry class.

Your lessons are brilliant! Best biology teacher I have ever had.
Your teaching has given me so much confidence in biology and has inspired
me to keep on learning more. It made a huge impact on my decision to go to med school :)
Thank you!

Thank you for all your effort put together on this site to make my Maths' problems solve. I learned a lot receiving lectures from you. You are the best that ever happen to me in this field. Maths made easy.

Professor, thank you very much for your detailed and helpful reply.  I have not known where to begin, and you have outlined it excellently.  I appreciate it a lot. - Best regards, Francisco

Dear Ms. Fung,

I love your teaching style! I am using Educator.com to refresh myself after 20 years out of high school. I am getting ready to take my SAT, and want the best score possible. Your courses are really helping me!

Thanks,
James

I've really enjoyed your lessons, Prof. Starkey!! They're VERY helpful, and they're the best chemistry video lectures I've found!

I also second Nawaphan's comment about possibly covering biological molecules in your lessons. Educator has a biochemistry section, but I think lessons with a chemistry perspective would very useful for us. My OChem class covers these biological molecules, and the last three chapters of my textbook concern these topics. Thank you!

Hi, I self study physics while in High school and I would like to say you are a truly remarkable teacher, I love your enthusiasm and the motivation you have brought me
Thanks so much!

Dr. Eaton I am so blessed to study with your lectures !!!
For real, you are the best science/biology teacher overall my high school experience!!!
Thank you so much.

Thank you professor, I like the way you do your lectures. You explain everything and try to keep everything simple for me to understand. Some other professors ,I have to say, try to make everything complex...I will say u are the best professor here in educator.com. Thanks.

you're a lifesaver. best teacher ever.

this is so much more helpful than school! thanks for being so clear

Hello Professor,

Thank you so much for your awesome lectures. I am sure that you are one of the best chemistry teachers in the nation :)

I have a question about example 5. I understand why the reaction has to be the first order, but why can't C and D be the answers? They are all first order reactions too. The only difference is that they are multiplied by 2 and 1/2.

Thank you so much!

I just love this website so much. Especially prof Goldwhite.

Thanks Raffi, I appreciate it! You have really helped me see the beauty in mathematics, ever since the multivariable calculus videos.  Your words of wisdom are inspiring! My passion is engineering, RF engineering to be more specific. I love putting the science behind the art! At the moment I am a bit of a math junkie, I love buying used math books on amazon, if you have any recommendations please let me know. Thanks again and best to you as well! Cary

Thank you so much professor Hovasapian, you're so wonderful, seriously! listening to your lecture is the best..... just want to make sure, when we do need ribose, and ribose only, we start from glycolysis, and then produce fructose 6 phosphate, and glyceraldehyde 3 phosphate, and HAVE THESE TWO MOLECULES TO go through non oxidative phase so that they can be turned into ribose, right? According to my study guide. Is this what they mean?  using the non oxidative pathway, but in the reverse direction from bottom to top, reaching ribose. Is my understanding correct? THank you!

Thank you Ms. Pyo for making this course effortless to learn. You are the best. Wish every math class on Educator was this crystal clear!!

Excellent, excellent I love it thank you so much Dr Carleen you me bless with your knowledge; I also found your video us full

seriously i LOVE THIS WEBSITE. I was just going to try an account for 1 month (well that is what i was thinking) This seriously the best education website i've ever tried, haha. And this was a website i came across thanks to youtubes commercial. First time ever i've tried to click on a commercial on youtube, but this looked really intressting so i did it. And i've not regreted doing so. I'm from sweden and i'm going to study on the university for another 5 years. Soooo, i think i will keep paying for this AWESOME lectures another 5 years. Cheers mates. Love you all. You make me like math even more because when educators teacher explain things, i actually understand what i'm doing. ONCE AGAIN, Thank you!

Best Regards Joel

Thanks SO SO much for the new video series! I was getting really worried that I wouldn't be ready for the Physics B exam and this is exactly what I needed and it was uploaded just when I needed it! Excellant organization and explanations!

educator.com has the best professors.

Dear Ms. Fung,

I love your teaching style! I am using Educator.com to refresh myself after 20 years out of high school. I am getting ready to take my SAT, and want the best score possible. Your courses are really helping me!

Thanks,
James