Question

Hi!
Could someone explain how does integral of 1/(1+x^2)= arctanx+c ?

Answer 1

do you know how to do trig substitutions?

Answer 2

I think I do.

Answer 3

\[x=\tan\theta\implies dx=\sec^2\theta d\theta\]

Answer 4

sub that in and follow it all the way through

Answer 5

Thank you very much!

Answer 6

welcome! let me know if you get stuck

Answer 7

Then do it for -inf to + inf......

Answer 8

why?

Answer 9

Just to see what it is.......

Answer 10

ah :)