What is the Integral of a Trigonometric Function with a Weird Substitution?

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Homework Statement



I need to calculate the integral:
\int_{0}^{\frac{\pi}{2}}\frac{\sqrt{\sin x}}{\sqrt{\sin x}+\sqrt{\cos x}}\mathrm{d}x

Homework Equations



The Attempt at a Solution


There is a tip: "try substituting y=\frac{\pi}{2}-x. I tried it and didn't get anywhere. I also tried several trigonometric identities.

Thanks in advance!
 
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Yeah you should probably try the suggested substitution again. Are you using the fact that sin(pi/2 - x) = cos x and cos(pi/2 - x) = sin x?
 
Ok, I got it now... Thanks! :)
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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