# Tricky Integral (for me anyway)

• Apr 19th 2010, 10:19 PM
p75213
Tricky Integral (for me anyway)
I am trying to figure this out and am stumped at the moment.

Find the integral of 1/(x^.5+1). Using U substitution I now have 2U/U+1. I know ln|U+1| is in the answer but I can't figure out what to do about the numerator.
• Apr 19th 2010, 10:40 PM
ione
Quote:

Originally Posted by p75213
I am trying to figure this out and am stumped at the moment.

Find the integral of 1/(x^.5+1). Using U substitution I now have 2U/U+1. I know ln|U+1| is in the answer but I can't figure out what to do about the numerator.

Divide 2U by U+1 to get $\displaystyle 2-\frac{2}{u+1}$

Now integrate
• Apr 19th 2010, 10:46 PM
harish21
Quote:

Originally Posted by p75213
I am trying to figure this out and am stumped at the moment.

Find the integral of 1/(x^.5+1). Using U substitution I now have 2U/U+1. I know ln|U+1| is in the answer but I can't figure out what to do about the numerator.

now only ln|U+1|, there is one more term in your answer.. look at the post above by ione and do the integration:

$\displaystyle 2 (\int 1 - \frac{1}{u+1} du)$
• Apr 20th 2010, 01:01 AM
p75213
Thanks guys. The long division was the key.