Question

Rewrite with only sin x and cos x.

cos 2x - sin x

Answer 1

@jim_thompson5910

Answer 2

Is this
$$
\cos^2x-\sin x\\
or\\
\cos 2x-\sin x
$$
?

Answer 3

the second

Answer 4

of which you provided

Answer 5

So,
$$
\cos 2x=\cos^2x-\sin^2x
$$
Combine this with \(\sin x\)

Answer 6

not sure how thats why im here

Answer 7

$$
\cos 2x-\sin x\\
=\cos^2x-\sin^2x-\sin x
$$
Make sense?

Answer 8

yep simply multiplied each side by sin x

Answer 9

No. I found \(\cos 2x\) in terms of \(\cos x\) and \(\sin x\) and then added to \(\sin x\), which is already in the form we desire.

Answer 10

alright, so the next step?