Question

Rewrite with only sin x and cos x. cos 2x - sin x helppp

Answer 1

well cos (2x) = cos^2(x) - sin^2(x)

and cos^2(x) + sin^2(x) = 1 so that means
cos^2(x) = 1 - 2 sin^2(x)

so you could rewrite the original as

1 - 2 sin^2(x) - sin(x)

does this help?

Answer 2

cos2x - sin2x - sin x

cos2x - sin3x

cos2x + sin2x + sin x

cos2x - 3 sin x

these are my choices. i feel like thats the simplified form of one of these im just not sure how to simplify them.

Answer 3

hm..

is the original expression

\[\cos(2x) - \sin (x)\]

?

Answer 4

yes