U sub and integration by parts

You have no fucking life, what the fuck are you even doing. Fuck calculus.

Fuck math. 2+2=4.

2+2=4. FUUUUUCCCKKKK YEEEAAAAAAA. UUUUUHHHHHHHHHHHHHHHH. YAAAAAAAAAASSSSSSSSSSSSSS.

KILL YOURSELF. AND THEN QUIT MATH.

Reverse chain rule in basically undoing the chain rule. If there is a function inside of another function that you are taking the integral of, you would need to divide the whole function by the inside function, after finding the integral of the outside function.

>>7691660
Do you divide the whole function by the inside function or the derivative of the inside function?

>>7691632
Integration by parts

>>7691664
Yes, I believe so. But also, FUUUCCCKKK MAAATHHHHH.

>>7691664
Where did you go? I'm so lonely...

>>7691693
Just learn integration by parts and u substitution. There's no real reverse chain rule, but one of those two methods will work always.

>>7691633
IBP is reverse of the Leibniz rule tho

>>7691781
> There's no real reverse chain rule

I wouldn't say that. I like to think of the "reverse chain rule" as integration by inspection. That is, just looking at the integral and being able to "see" what the antiderivative is, which generally requires you take the chain rule backwards in your head.

Other than that though, I agree, it's not very useful except for those rare cases where it's quicker than actually working things out.

>>7691856
>integration by inspection
90% of the time you do a u-sub this is exactly what you're doing anyway.

>>7691781
>one of those two methods will work always
Haha no
The integral of exp(x*x) is unexpressable in terms of elementary functions, for instance.