Answer:
x = 138.6° or 221.4°
Step-by-step explanation:
2sin2x + 3sinx = 0
(From trigonometry identity: sin2x = 2sinxcosx, therefore, 2sin2x = 4sinxcosx)
4sinxcosx + 3sinx = 0
4sinxcosx = -3sinx
4cosx = -3 (Divide both sides by sinx)
cosx = -3/4
x = arccos(-3/4)
x = 138.6° ( Second quadrant) or
x = 41.4 + 180 = 221.4° (Third quadrant).
