Question

Help with: cos^2x - (sin^2x)(cos^2x)

Answer 1

Maybe divide the cos^2x's out?

Answer 2

you mean factor out cos^2 x ... yes.

Answer 3

Which would leave you with 1 - sin^2x, correct? Except that's not one of the answer choices.

Answer 4

then use the identity

\(\sin^2 x + \cos^2 x = 1\)

Answer 5

so whats 1- sin^2 x = ...?
from the above identity?

Answer 6

cos^2x, but that's not an answer choice either, lol.

Answer 7

there is a factored out cos^2 x too, right? :)

Answer 8

\(\Large \cos^2 x \times \cos^2 x = ...?\)

Answer 9

cos^4x, that is an actual choice. Thank you!

Answer 10

i will write out the steps,
\(\Large \cos^2 x - \sin^2 x \cos^2 x = \cos^2 x (1- \sin^2 x ) \\ \large = \cos^2 x \times \cos^2 x = \cos^4 x \)

and welcome ^_^