Question

2sen²x + 3 sen x-2=0

Answer 1

2sen²x + 3 senx - 2=0
2senx                  -1
1senx                 +2

4senx - senx =  3senx

(2senx - 1)(senx + 2) = 0

2senx - 1 = 0          senx + 2 = 0
2senx = 1               senx = -2

$senx = \frac{1}{2}$             $senx = -2$

CS = (-2; 1/2)