posted by Stuck .
"Find the antiderivative of f(x)= (2x)/((x^2)+1)."
I understood how to do it with just a number as the numerator, but I can't figure it out with x in the numerator..
antiderivative of f(x)= (2x)/((x^2)+1)
let u = x^2+1
then du = 2 x dx
and you have
ln u + c
ln (x^2+1) + c