# Math Help - Powers of Trigonometric Functions

1. ## Powers of Trigonometric Functions

$8 cos^2 x$

Rewrite the expression as an equivalent expression that does not contain powers of triogonometric functions greater than 1.

2. Originally Posted by purplec16
$8 cos^2 x$

Rewrite the expression as an equivalent expression that does not contain powers of triogonometric functions greater than 1.
power reduction identity ...

$\cos^2{x} = \frac{1+\cos(2x)}{2}$

... it comes from the double angle identity for cosine.