Question

use power reducing formula to write cos^4 x sin^4 x in terms of the first power of cosine

Answer 1

Recall
\[\cos^2(x) + \sin^2(x)=1\]

Answer 2

\[\sin^2(x)=1-\cos^2(x)\]

Answer 3

\[\cos^4(x)(1-\cos^2(x))^2\]

Answer 4

\[=\cos^4(x)(1-2\cos^2(x)+\cos^4(x)\]

Answer 5

or you may use
\[\sin^2(x)=\frac{1-\cos(2x)}{2}\]

Answer 6

this way you can reduce the power