Trig math help please?

2sin(x) + 1 = 0
2sin(x) = -1
sin(x) = -1/2

Since sin(30°) = 1/2, then
x = (180° + 30°) or x = (360° - 30°)
x = 210° or x = 330°

If 180° ≤ x ≤ 270°, then x = 210°
If 270° ≤ x ≤ 360°, then x = 330°

sin x = - 1/2
sin x = 210⁰ , 330⁰

sin (x) = -1/2

since the sin (x) value is negative, it must be in 3rd quadrant
(180° ≤ x ≤ 270°) & 4th quadrant (270° ≤ x ≤ 360°)

sin^-1 (1/2) = 30°

therefore
(a) If 180° ≤ x ≤ 270°, then x = ___°. (Answer:180+30=210)
(b) If 270° ≤ x ≤ 360°, then x =____ ° (Answer:360-30=330)

2sin(x) + 1 = 0
2sin(x) = -1
sin(x) = -1/2
the sine function is negative in quadrants 3 and 4
in quadrant 3 which is between 180 and 270 degrees the answer is 7pi/3 and in the fourth quadrant which is between 270 and 360 degrees the answer is 11pi/3.