Use the power reducing formulas to rewrite the expression in terms of first powers of the cosines of multiple angles.

Question

sin²(4x)cos²(4x)

Please help, I don't understand how to power reduce this!

Answer 1

[sin² (4x)] [cos² (4x)]

[(1 + cos 8x) / 2] [(1 - cos 8x) / 2]

(1 - cos² 8x) / 4

[1 - (1 - cos 16x) / 2] / 4

cos 16x / 8

Answer 2

A lot of formula manipulation so I felt a video was best to show the power-reducing formulas in action. I hope this helps!