Evaluate each of the following integral: `int_0^picos^5x\ dx`

Explanation

`I=\int_{0}^{\pi} \cos 5 x d x`
`I=\int_{0}^{\pi} \cos 4 x \cdot \cos x d x`
`I=\int_{0}^{\pi}(\cos ^{2} x)^{2} \cdot \cosx d x`


`I=\int_{0}^{\pi}(1-\sin ^{2} x)^{2}-\cos x d x`


Let `\sin x=t`


`I=\int_{0}^{0}(1-t^{2})^{2} d t`




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