MHB Evaluating $\int_{-1}^{1}\sin^7\left({x}\right) \,dx$ Using $u$-Substitution

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The integral $\int_{-1}^{1}\sin^7(x) \,dx$ can be evaluated using the property of odd functions. Since $\sin^7(x)$ is an odd function and the limits of integration are symmetric about the origin, the areas under the curve on either side of the y-axis cancel each other out. Therefore, the value of the integral is zero. This conclusion is reached without further calculations, leveraging the odd-function rule directly. The final result is that the integral evaluates to 0.
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$\int_{-1}^{1}\sin^7\left({x}\right) \,dx$
$u=\cos\left({x}\right)$
$du=-\sin\left({x}\right)$
So
$-\int_{-1}^{1} \left(1-{u}^{2}\right)^3\,du$
So continue?
 
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Your integrand is odd, and the limits symmetric about the origin, so can you think of a shortcut you can use?
 
I presume you mean the areas will cancel out and the answer will be zero for interval given?
 
karush said:
I presume you mean the areas will cancel out and the answer will be zero for interval given?

Yes, the odd-function rule can be directly applied here to state that the given definite integral has a value of 0. :D
 

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