1. sin (π/2 - 2x) = 1/2 sin (90° - 2x) = sin 30° 90° - 2x = 30° 2x = 90° - 60° x = 30°/2 x = 15°
sin (90° - 2x) = sin 150° 2x = 90° - 150° x = -60°/2 x = -30° x = 360° - 30° x = 330°
HP = {15° , 330°}
2. cos² x + 3 sin x + 3 = 0 (1 - sin² x) + 3sin x + 3 = 0 -sin² x + 3sin x + 4 = 0 (-sin x + 4)(sin x + 1) = 0 sin x = -4 (tdk memenuhi) sin x = -1 ---> x = 270°
Verified answer
1.sin (π/2 - 2x) = 1/2
sin (90° - 2x) = sin 30°
90° - 2x = 30°
2x = 90° - 60°
x = 30°/2
x = 15°
sin (90° - 2x) = sin 150°
2x = 90° - 150°
x = -60°/2
x = -30°
x = 360° - 30°
x = 330°
HP = {15° , 330°}
2.
cos² x + 3 sin x + 3 = 0
(1 - sin² x) + 3sin x + 3 = 0
-sin² x + 3sin x + 4 = 0
(-sin x + 4)(sin x + 1) = 0
sin x = -4 (tdk memenuhi)
sin x = -1 ---> x = 270°
HP = {270°}