∫▒x^3/(1+x^2 ) dx
This is the question I have. It's quite a mind boggler (well, for me)
It has to do with further substitution with integration.
This is what I did, but I got the wrong answer in the back of the book.
Let u = 1+x^2
du/dx = 2x
du/2x = dx
=1/2 u- 1/2 lnu
=1/2(1+x^2 )-1/2 ln(1+x^2 )+c
I have a feeling it's something with my substitution