- #1
Shannabel
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Homework Statement
find the integral from 1 to infinity of (arctanx/x^2)dx
Homework Equations
The Attempt at a Solution
i used integration by parts:
u=arctanx
du=1/(1+x^2)dx
dv=x^-2dx
u=(-1/x)
-arctanx/x + [(1/(x)(1+x^2))dx]from 1 to infinity
i have a partial solution in my book, and here it suggests that i change the integrand to
(1/x)-(x/(1+x^2)) which if i work backward, i can see is equal to the original integrand, but i don't see how to get from (1/(x)(1+x^2)) to (1/x)-(x/(1+x^2))
help?