Question

Completely simplify: (cos θ − sin θ)^2

Answer 1

whats the expansion of the perfect square?

Answer 2

its just like expanding

\[(a -b)^2=\]

Answer 3

Im sorry I was having trouble viewing your response but yes a^2 -2ab+b^2

Answer 4

I got cos^2x-2cosxsinx+sin^2x but it is not correct :/

Answer 5

you expansion is correct but what do you know about

\[\cos^2(x) + \sin^2(x) \]

Answer 6

which are both terms in the expansion.

Answer 7

oh it equals 1!

Answer 8

so make the substitution and your answer should be correct