2cos^2×-5cos×+2=0 , 0<×<2pi. adalah.... plis jawab yg betul...

Trigonometri

2cos²x - 5cos x + 2 = 0
Utk 0 < x < 2π
= 0< x < 360

Misal cos x = a

2a² - 5a + 2 = 0
(2a - 1)(a - 2) = 0
a = 1/2 atau a = 2 --> Tdkmemenuhi


a = 1/2
cos x = 1/2
Kemungkinan ada di K.I atau K.IV
utk K . I

cos x = 1/2
x = 60°

utk K . IV
cos x = cos (360-x)
cos 60 = cos (360-60)
cos 60 = cos 300

Hp = {60° , 300°}