Question

Tentuka himpunan penyelesaian cos3x=1/2√3 untuk x=0°<_x<_360°

Answer 1

Cos 3x = 1/2 √3 = cos 30
3x = 30 + K. 360  atau 3x = -30 + k. 360
x = 10 + k. 120 atau x = -10 + k. 120
k = 0,1,2,3.....

k = 0 --> x = 10, -10
k =1--> x = 120, 110
k = 2 --> x = 250, 240
k = 3 --> x = 370, 350

0 <= x <= 360  maka
hp  x = (10,110,120,,240, 250, 350)