How do you evaluate: indefinite integral (1+x)/(1+x^2) dx?

1 Answer
Mar 24, 2018

The answer is =arctanx+1/2ln(1+x^2)+C

Explanation:

The integral is

I=int((1+x)dx)/(1+x^2)=int(dx)/(1+x^2)+int(xdx)/(1+x^2)

The first integral

int(dx)/(1+x^2)=arctanx

And the second integral is

int(xdx)/(1+x^2)=1/2int(2xdx)/(1+x^2)

=1/2ln(1+x^2)

And finally

I=arctanx+1/2ln(1+x^2)+C