Question

please help.
find the derivative of z=1/2x+1/4 sin2x.

i only got 1/2+1/2 cos2x but my book says cos^2x... pleaaseee

Answer 1

use the double angle identity

\[cos2x = 2 cos^2 x - 1\]

Answer 2

is it really necessary to use the cos2x=2cos^2x-1? can i not use 1-2sin^2x which is also equals to cos2x?

Answer 3

@IrishBoy123 ? pleaaasseee

Answer 4

of course you can, go for it

see where each takes you, circle back if unsure:p