Question

Tolong ya....
1. jika cos x = sin 2x. maka sin x.cos x?

Answer 1

Cos  x=2sin x cos x
cosx/cos x = 2 sin x
1=2 sin x
sin x = 1/2
cos x = 1/2 √3

sinx cos x = 1/2 x 1/2√3 = 1/4√3

Answer 2

Cos x = sin 2x
cos x = 2 sin x cos x
1 = 2 sin x
1/2 = sin x
sin 30 = sin x
x = 30


Nb : Nilai sudut berulang tiap 360 derajat.
       x = 30 + k.360 dan x = 150 + k.360