Hp dari 2 sin 4x -1 = 0 , 0 < x < 2π

2 sin 4x - 1 = 0
sin 4x = 1/2
sin 4x = sin phi/6

4x = phi/6 + k.2phi
x = phi/24 + k.phi/2

k = 0, x = phi/24
k = 1, x = 13phi/24
k = 2, x = 25phi/24
k = 3, x = 37phi/24

4x = 5phi/6 + k.2phi
x = 5phi/24 + k.phi/2
k = 0, x = 5phi/24
k = 1, x = 17phi/24
k = 2, x = 29phi/24

Hp = {phi/24 , 5phi/24 , 13phi/24 , 17phi/24 , 25phi/24 , 29phi/24 , 37phi/24}