Jawabanmu

2014-05-19T08:03:54+07:00
Cos 2x - sin x = 0
cos 2x = sin x
cos 2x = cos (90 - x) -> cos nya bisa dicoret/dihilangkan
2x = 90 - x
3x = 90
x = 30

Jadi cos 2x - sin x = 0
cos 2(30) - sin 30  = 0
1/2 - 1/2 = 0

Berarti benar x nya = 30 ^^
1 5 1