himpunan penyelesain dari cos x=cos 5/12π untuk 0

cos x = cos 5/12π
x = 5/12π + k.2,π
k = 0, x = 5/12π
k = 1, x = 5/12π + 2π. => x = 29/12π ( tidak dipakai )
Jadi x = 5/12π

cos x = cos 5/12 phi
x = 75

x = 75 + k. 360
k = 0, x = 75

x = -75 + k. 360
k = 1 , x = 285

HP = ( 5/12 phi, 57/72 phi)

maaf kalo salah