# Thread: finding the integral possbily u sub?

1. ## finding the integral possbily u sub?

$\displaystyle \int_0^1 {\frac{{{x^{\frac{1} {2}}}}} {{{{(1 - x)}^{\frac{1} {2}}}}}dx}$

I am thinking u substitution but I am not sure what to sub in

2. Originally Posted by genlovesmusic09
$\displaystyle \int_0^1 {\frac{{{x^{\frac{1} {2}}}}} {{{{(1 - x)}^{\frac{1} {2}}}}}dx}$

I am thinking u substitution but I am not sure what to sub in
See here: - Wolfram|Alpha

Be sure to click on Show steps.

3. can't you do a trig sub with arc sin because the bottom is (1-x)^.5

4. Originally Posted by genlovesmusic09
can't you do a trig sub with arc sin because the bottom is (1-x)^.5
But the derivative of arcsin is $\displaystyle \frac{1}{(1- x^2)^{.5}}$, not $\displaystyle \frac{1}{(1-x)^{.5}}$.

5. Originally Posted by HallsofIvy
But the derivative of arcsin is $\displaystyle \frac{1}{(1- x^2)^{.5}}$, not $\displaystyle \frac{1}{(1-x)^{.5}}$.
but if i do a u sub where u=x^.5 then x=u^2
so it would be u/(1-u^2)^.5

6. Originally Posted by genlovesmusic09
but if i do a u sub where u=x^.5 then x=u^2
so it would be u/(1-u^2)^.5
No it doesn't. Have you considered what dx becomes ....?