Question

Show that the equation is not an identity by finding a value of x for which both sides are defined but not equal. cos x - cos x sinx = cos3 x

A. π

B. 0

C. pi/4

D. pi/2

Answer 1

@genius12

Answer 2

I thought it was D but it isn't. I apparently don't know how to work it out.

Answer 3

\(\bf \huge Try \ \ x=\frac{\pi}{4}\).

@SPrezzy

Answer 4

Thanks!