Question

\[\int\limits_{-\pi/8}^{\pi/8} \cos^3 (4x)\]

I set it equal to cos(4x) * (1-sin^2(4x)) good so far?

Answer 1

yes that seems pretty good, now multiply things out.

Answer 2

Then I went u = sin(4x), du = 4cos(4x), and implemented 1/4 du.

Answer 3

You seem to do everything right so far, I would recommend you to just carry out the steps and then tell us if you're stuck somewhere.

Answer 4

Thanks, I made a small error. I got 1/3 as my answer.

Answer 5

well done!
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