How do you integrate int x/((x^2+1)^2) using partial fractions?

1 Answer
Feb 21, 2016

Rather than using partial fractions, we can make a simple substitution to find that

intx/(x^2+1)^2dx=-1/(2(x^2+1))+C

Explanation:

Rather than partial fractions, this is easiest to solve through integration by substitution.

Let u = x^2 + 1. Then du = 2xdx and so we have

intx/(x^2+1)^2dx = 1/2int1/(x^2+1)^2*2xdx

=1/2int1/u^2du

=1/2(-1/u + C)

=-1/(2u)+C

=-1/(2(x^2+1))+C