cos = -1/2akar 3,0°< x < 360°

Bab : Persamaan Trigonometri
Kelas : XI SMA

cos x = -1/2 V3
cos x = cos 150°
x = 150°

Rumus cos :
=> x = cos x + k . 360
=> x = - cos x + k . 360


Step I :

x = cos x + k. 360°
x = 150° + k . 360°
----------------------------
k = 0
=> 150° + 0.360° = 150° ( M )
k = 1
=> 150° + 1.360° = 510° ( TM )

Step II :

x = -cos x + k. 360°
x = -150° + k . 360°
----------------------------
k = 0
=> -150° + 0. 360° = -150° ( TM )
k = 1
=> -150° + 1. 360° = 210° ( M )
k = 2
=> -150° + 2 . 360° = 570° ( TM )

Jadi , Hp = { 150° , 210° }