Question

Himpunan penyelesaian persamaan cos 2x°+2 sinx°-1=0 pada interval 0≤x≤360 adalah..
A.{0,90,180}
B.{0,30,120}
C.{0,30,120,210}
D.{30,120,210,330}
E {30,150,240,330}

Answer 1

Cos 2x + 2 sin x -1 = 0
1- 2 + 2 sin x - 1 = 0
2 sin x - 2 = 0
2 sin x ( 1 - sin x) = 0
sin x = 0 atau sin x = 1
A . {0, 90, 180}