Materi TRIGONOMETRI Tingkat X SMA

2 cos (2x + 5/6phi) = akar3
cos (2x + 5/6phi) = 1/2akar3

nilai 1/2akar3 ada di kuadran 1 dan 4, yaitu 30' dan 330'

2x + 5/6.180
2x + 150 = 330
2x = 180
x = 90
x = 1/2phi

2x + 150 = 30
2x = -120
x = -60
x = 300
x = 120
x = 2/3phi

#CMIIW

2 cos (2x +5/6 μ) = √3
cos (2x + 150 ) = 1/2 √3

catatan :
0 <= x >= 180˚


cos 330˚ = 1/2 √3
cos ( 360 + 30 ) = 1/2 √3


o> cos ( 2x + 150) = cos 330
2x + 150 = 330
2x = 330 - 150
2x = 180
x = 90
x = 1/2 μ

o> cos (2x + 150) = cos ( 360 + 30)
2x + 150 = 360 + 30
2x + 150 = 390
2x = 240
x = 120
x = 2/3 μ

Hp ( 1/2 μ , 2/3 μ ) .........B