Difficult trignonometric Integral

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Homework Statement


I need to find \int_{0}^{\pi}(sin(x)^{2n})dx.

My idea was to write sine in the exponential definiton and use binomial theorem but i don´t really get anywhere :(

Any suggestions ?
 
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If you integrate by parts, you get a recursive formula for \int (sin(x)^{2n})dx in terms of something like sin(x)^{2n-1} by differentiating sin to the power of 2n-1, and integrating a sin. My guess is that'll do the trick
 
hmm yea found that but i need an absolute formula if there even is one ?
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
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