To start, make things easier to see by substituting x for sin x. The equation then can be written as 2x^2 + 3x +1. This factors as (2x+1)(x+1). Rewriting in the proper form (2 sin x + 1)(sin x +1). The solutions would be where sin x = -1/2 (7pi/6 and 11pi/6) and sin x = -1 (3pi/2). Choice A