Question

rewirte -12sin(3x)cos(3x) to become 36sin^2 (3x) - 36 cos^2(3x)

Answer 1

allready tried using: sin3x= 3sin x – 4sin³ x
and cos3x= 4cos³ x – 3cos x

Answer 2

looks that's not an identity

Answer 3

put x=0, to -12sin(0)cos(0)
it is 0

while, 36sin^2 (0) - 36 cos^2(0)
it is -36

they are not same :)

Answer 4

agreed.

Answer 5

thanks :)

Answer 6

i will check what the typo is.

Answer 7

yes, i think there is a bit typo