Originally Posted by

**kinetix2006** ----------------------------------------------------------

Integrate x^(1/2) / (1 + x) dx

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I substituted x^(1/2) = sin y

so it becomes Integral of 2*tany*siny dy

then integration by parts its

2*(tany*cosy - Integral of (-secy) dy)

= 2ln| sec y + tan y | - 2 siny

then substituting x back in

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

but the answer in the back of the book is

2x^(1/2) - 2tan^-1( x^(1/2) )

If anyone can tell me what I'm doing wrong it will be much appreciated