Tentukan hp dari pesamaan 2 cos 2x + √3 = 0 dan 0°≤ x ≤ 720°

2 cos 2x + √3 = 0
cos 2x = -√3/2
cos 2x = cos 150°

2x = 150 + k.360
x = 75 + k.180
k = 0, x = 75°
k = 1, x = 255°
k = 2, x = 435°
k = 3, x = 615°

2x = -150 + k.360
x = -75 + k.180
k = 1, x =105°
k = 2, x = 285°
k = 3, x = 465°
k = 4, x = 645°

Hp° = {75°, 105°, 255°, 285°, 435°, 465°, 615°, 645°}