Question

Cos x = 2 sin x, maka nilai sin x cos x adalah.........

Answer 1

cos x = 2 sin x

cos x = 2 (1 - cosx)
cosx = 2 - 2 cos x
cos x + 2cos x =2
3 cos x = 2
cos x= 2/3

cos x = 2 sin x
2/3 = 2 sin x
2/3/2=sinx
2/3 ×1/2 = sin x
2/6 = sin x
sin x = 2/6

jadi,
sin x cos x = 2/6 . 2/3 = 4/18 = 2/9

Answer 2

Cos x = 2 sin x
cos x = 2 (1 - cosx)
cosx = 2 - 2 cos x
cos x + 2cos x =2
3 cos x = 2
cos x= 2/3
cos x = 2 sin x
2/3 = 2 sin x
2/3/2=sinx
2/3 ×1/2 = sin x
2/6 = sin x
sin x = 2/6
sin x cos x = 2/6 . 2/3 = 4/18 = 2/9