Question
How do you express sin4x as a trigonometric function of x?
Answers
use angle identities
sin 2a = 2 sin a cos a
cos 2a = co^2a - sin^2 a
use them once for a = 2x
then again for a = x
sin 2a = 2 sin a cos a
cos 2a = co^2a - sin^2 a
use them once for a = 2x
then again for a = x