Question

Rewrite with only sin x and cos x.

cos 2x - sin x

Answer 1

Answers are:

A. cos^2x-sin^2x-sinx
B. cos^sx-sin^3x
C. cos^sx+sin^2x+sinx
D. cos^sx-3sinx

Answer 2

cos(a+b)=cosa cos b -sin a sin b
put a=b=x
cos(x+x)=cos x cos x-sin x sin x
\[\cos 2x=\cos ^{2}x-\sin ^{2}x\]
now you can write the solution

Answer 3

how do i do that? thanks btw :)

Answer 4

\[\cos 2x-\sin x=\cos ^{2}x-\sin ^{2}x-\sin x\]

Answer 5

Thank yu so mucH!!!

Answer 6

yw