4 sin2x-12 sin x +5=0

4 sin² x - 12 sin x + 5 = 0
Misal sin x = p

4p² - 12p + 5 = 0
(2p - 5)(2p - 1) = 0
p = 5/2 (tm)
p = 1/2
sin x = 1/2
sin x = sin 30°

x = 30 + k.360
k = 0, x = 30°

x = 150 + k.360
k = 0, x = 150°

Hp = {30°, 150°}