Question

Use the formulas for lowering powers to rewrite the expression in terms of the first power of cosine.
-cos(x)sin^2(x)
-cos^7(x)

Answer 1

Use the double angle formula
\[
\cos^2(x) =\frac {1+\cos(2x)}2\\
\sin^2(x) =\frac {1-\cos(2x)}2\\

\]

Answer 2

yes I have used the formulas. I used cos x sin^2x and have gotten it wrong?? please help :(
\[(\cos(x)-\cos^2(2x))/2 \]

Answer 3

\[
-\cos(x)\sin^2(x)=\frac {-\cos(x)+\cos(x)\cos(2x)}2\\
\]

Answer 4

isn't cos(x)cos(2x) the same thing??

Answer 5

--- as cos^2x?