Great video. Thanks for giving Feynman props. In “Surely You’re Joking, Mr. Feynman”, Feynman talks about how he was always the integral guy at MIT, Princeton, and while working for Manhattan Project at Los Alamos. It came from his unique tool box of math tricks he learned from “Advanced Calculus” by Woods, which his HS physics teacher forced him to read since he was too talkative in class (because he was bored).

I screamed out with joy when the natural logs canceled... it's a habit.

Lab partner: We need to calculate this integral asap! Me: Nah bro, just use the Simpson method.

I finished his book "Surely you're joking, Mr. Feynman" less than an hour ago, he mentions this in the book, so finding this in my recommendations was a pleasant surprise.

This video just made my integral life wayyyyyy much easier. Also really thanks to Sir Feynman!

Took Calc 50 years ago but I could still follow this. One of my profs said Calc will stay with you all of your life. I'm amazed.

I have been a subscriber of you for a few months now. I was reading "surely you're joking Mr Feynman" and got to the chapter where he talks about this thing I hadn't been taught, so I decided to google it and found a video of you explaining it! Haha cheers from a physics student in Chile!

This is so awesome! Feynman describes using this technique in 'Surely You're Joking'. I was very curious to what that technique was, even asked some teachers, but I never did find out. I very happy to finally know the approach!

I love that I can finally understand one of your videos. Whenever you talk about nabla this and nabla that I have no clue what you're saying, but when you talk about pure maths everything clicks.

Great video, Mr Maths. Feynman was a genius physicist and probably one of the best teachers of science at every level EVER! He will live on forever

I was never taught this method, and was completely unaware of its existence until I watched blackpenredpen integrate sinc(x) over the non-negative domain. It was a revelation! I love this method, it is sooooo cool!

Andrew you are my savior. I have spent hours trying to figure this out from professors notes for the final and you explained this amazingly

That's badass. A very cool technique to be sure. I'll have to find to practice examples to try it out on. Thx for sharing it.

Awesome video! Even though I am rusty with calculus, I can still appreciate the elegance of this method, and maybe this is just what I need to motivate me to jump back into this material with both feet!

Isnt this practically just the Leibniz Integral rule?

I remember looking at this years ago - thinking it made no sense at all. I looked at it again today after being introduced to "Differentiation Under The Integral Sign" in my PDE class and gosh....it feels so good to understand how the heck this works.

Bro your handwriting is beautiful. Especially your “d”s

a year ago, i watched this vid and understood nothing (cuz was dumb). still dumb but with some more knowledge and the video was so helpful. thank you andrew.

It’s crazy when you just take a step back, and everything becomes so easy and clear.

Because you're so serious in your jokes, being serious here makes me think you're joking

There was something really satisfying about your marker pens. Keep that up and you’ll have a fan for life.

My teacher was one of Feynman’s first students. It’s cool to see this video recommended like this. I have an exam tmrw wish me luck guys.

Andrew Dotson, I like this integral you chose to demonstrate Dr. Richard Feyman"s technique. I admire the way you explained here in a clear, timely and patient manner. Thanks Andrew and Dr. Feyman.

You made my day! The method looks amazing. We learned it in class, but never understand it right as I did here! Thank you!

I was never taught this, so it's nice to finally learn this technique. I think there are some integrals I need to retry now...

I have seen several videos of this technique on KZfaq, but this is the clearest! Thanks.

I just found out this video 2 years later after it was uploaded and i am hopefully going to go to university next year to study physics. I have been watching your content for a while but i never went into the math videos because i am only graduating highschool and i only know how to integrate and how to take derivative of a function. I havent taken calculus but in Turkey our education system in highschool is a little bit harder. We take beginners level QM (basically starting from bohr and ending with coumpton event and debroglie wavelenght but no complex math we just learn the formulas and the philosophy behind them.), we take organic chemistry which was almost university level but now they simplified it a lot idk why it used to be like that glad that i didnt have to go through that lol. And we end math class with chamber analytics after we learn integral. Well as much as i know it was calculus level before but it was simplified couple of years ago. So i only knew integration techniques and ya know how to find an area under a function and some simple problems with integration/derivation. I dont know how to get an integral of natural log so i was curious about the video because those parts were cut out from our education system few years ago as i said. Soooo you didnt really need to know these but i just wanted to tell because i wanted you to know that i wasnt really at this level yet (even though its basic and i know some of it from my own research apart from school) and i really really enjoyed the video. You explained it really well and this was uploaded on feynmans bday unironically. I ejaculated after the ln(t)s disabled each other (jk jk). Thanks andrew, i love your videos! Greetings from Turkey!

i love how i've watched this 3 times but still don't fully understand it yet

That was a great explanation of the method. Good work!

Math tricks like these are so cool. Thanks for the video

Richard Feynman made this tidbit of advanced calculus quite famous. I printed out the PDF of Advanced Calculus which he used back then and lo and behold it was in there!

Watching him make sure the equation for integrating a to the power x was right multiple times in his head to make the vdo in one take was hilarious 😂

Our university SQU recommends your video for independent learning 👍🏻

I love it. It is so nice. You differentiate with one variable and integrate with the same variable. I don't care who made it. It's genius

Sup! That was a really good explanation. Can you please provide some more examples of where we can apply this kinda technique?

Wtf just happened... Feel like the education system has been holding back *history channel alien music starts*

This is one of my favourite technique.

It was fun. I really enjoy watching it and I am going to watch it again. Thanks🙏😊

Thanks this is a great video on how to do Feynman integration really appreciate it.

I love that technique!!! Great presentation!!

T is the thing we will use to exploit the integral. WITH RESPECT TO T.

Great! Can you talk about this being a special case of the Leibniz rule for integration?

One of the better explanations. Thanks.

This was an awesome video and I love this method.Thank you.

Thanks again very calm explanation is easy to absorb 😎😍

i honestly love your beard.

Does it work for indefinite integrals?

Talking at the camera (mike) and then at the board is like the scene from 'Singing in the Rain'!

I have never seen this, but I remember applying something like this when I got stuck. Nice to know how it is formally done!

Our advanced calculus professor gave us almost the exact same integral for one of our quizzes lol. It was integral from 0 to 1 of (x^2-1)/lnx, which is basically g(2) for g as defined in your video lol. So the final answer ended up being ln(2+1) = ln3 as the final answer.

my calc 2 professor knew this would be too powerful to teach this

I love this method. 💙

Awesome! After finishing calc I wanted to know some other methods, and since I always study physics, Feynman's was always mentioned in some of my books.

Excellent presentation of the topics in a beautiful manner. Thanks.DrRahul Rohtak Haryana India

Excellent explanation!

Bro I'm in calc 2 and we just finished trig sub and did by parts, and I kind of knew vaguely about this but not really, and now I'm about to watch all the lectures cause that was neat

I tried it myself but used [(t^3 - 1) t^x]/ln(t) as the integrand. You get the same answer but have to consider g(x) as x approaches infinity to get the integrating constant. :)

Im probably late, but thanks for the vid bro, this helped me learn about Feynman's technique to integrate. It is out of portions for me currently, but it is interesting nonetheless.

You did a nice job explaining this.

You should do a review of the looks at the met gala it'll be fun

Fascinating technique

Woah! Nice vid. Thanks for showing this method of integration.

Something confused me, 7:21 why is g(x=0) the integral of 0 to 1 of 0dt?? Wouldnt it be the integral of -1/ln(t) from 0 to 1? Since you are replacing X not t, also that poses another problem, you are integrating the function for t=0 on a ln(t) which would be undefined, and also t^0 would also be undefined... Is it that trivial? Please tell me :(

IM LOVIN THIS❤❤

I knew this method too! Thanks for showing it to us! REALLY COOL! HBD FEYNMAN!

Hey thanks for these integrals videos they're being very helpful for my 2nd year in physics

Absolutely brilliant video and explanation.

Assum e=3 and proceed

Certainly not in the BC calc curriculum

Hey man, love ur videos! But I have a question, this integral seems to be a type 2 improper integral. Why didn’t you evaluate as an improper integral?

WOW! So beautiful! Thank you!!

Came here once in grade 10 and it was too early. Now I come back and get ready to beat my calc 2 teacher exam

Would be nice if you'll make a video just solving integrals for a couple of hours :)

You're they Ryan Reynolds of Mathematics. Keep it simple, that's cool👍

Great explanation,thank you so much

This is why I love integration

Fantastic.

Very good. And useful.

This was such a class video well in mate

Feynman is greatest physicist of all times.

Super cool! Easy to follow as well

Alternative way of doing the final step (after g' is found) that doesn't require you to find the constant of integration: g(3) = g(0) + \int_{0}^{3} { g'(x) dx }.

That was actually really cool and haven't come across this yet.

This is happiness

Gonna try this Electrostatics

Wow that was so amazing

Richard Feynman is my favourite physicist

Thanks man That helps a lot

Could you have dealt with the logarithmic function in the denominator instead, and could have gotten to the same answer via Feynman’s method

I've always wanted to learn how to do this!

Very clear!

Thanks a ton!

You just gained a subscriber

That was really interesting. Never seen that before.

Interesting method! Very cool thx bro

Actually Feynman did not invent this technique , this technique was mentioned in an unpopular book of Integrals in Feynman's time, he was lucky to find it.

Didn't get why we put 0 to get c

Dude. Please do more videos like this

Amazing

I know the original integration went from 0 to 1 interval... Is this interval baked into the g'(x) and/or g(x) functions? I know the initial condition was used when he plugged in x=0, but I'm not sure when the end of the interval, i.e. 1, was used. Any clarification would be greatly appreciated.