Question

Find the derivative w = sin⁴ y cos⁴y.

Answer 1

W = sin⁴y cos⁴y

\(\frac{dW}{dy}\) = sin⁴y \(\frac{d}{dy}\) cos⁴y + (\(\frac{d}{dy}\) sin⁴y) cos⁴y

 = -4 sin⁴y cos³y sin y + 4 sin³y cos y cos⁴y

 = 4 sin³y cos³y (cos²y - sin²y)

 = 4 sin³y cos³y cos 2y