Question

please help!! medals given
rewrite the expresion cos^4x
as an equivalent expression that does not contain powers of trigonometric functions greater than 1

Answer 1

@Nnesha

Answer 2

@freckles

Answer 3

@asnaseer

Answer 4

@Loser66

Answer 5

@phi

Answer 6

\[ \cos^2(x) = \frac{1}{2}(1 + \cos(2x)) \]
\[ \cos^4x = \cos^2 x \cdot \cos^2 x = \frac{1}{2}(1 + \cos(2x))\frac{1}{2}(1 + \cos(2x)) \]

Answer 7

you can multiply out
\[ \frac{1}{2}(1 + \cos(2x))\frac{1}{2}(1 + \cos(2x)) = \frac{1}{4} (1+\cos 2x)(1+\cos 2x) \]
and then try simplifying again

Answer 8

@ganeshie8

Answer 9

@AlexandervonHumboldt2

Answer 10

\[\frac{ 1 }{ 4}(1+\cos(4x)\]

Answer 11

what do i do next?

Answer 12

@Directrix