Question

Selesaikan untuk (0 < x < 2pi)
A. 2 cos 2x -1 = 0
B. 2 sin²x + 3 sin x = 0

Answer 1

Verified answer

Bab Trigonometri
Matematika SMA Kelas X

A] 2 cos 2x - 1 = 0
2 cos 2x = 1
cos 2x = 1/2
2x = π/3
x = π/6

2x = 5π/3
x = 5π/6

HP = { π/6, 5π/6 }

2] 2 sin² x + 3 sin x = 0
sin x (2 sin x + 3) = 0
sin x = 0
x = 0
x = π

2 sin x + 3 = 0
2 sin x = - 3
sin x = -3/2 (tidak memenuhi)

HP = { 0, π }