2 sin^2 x - 3 sin x + 1 = 0 factor as :
(2sinx - 1) (sinx - 1) = 0
Now, either
2sinx - 1 = 0 → sinx = 1 / 2 and this occurs at 30° and 150° on the given interval
OR
sinx - 1 = 0 → sin x = 1 and this occurs at 90°
Here's a graph of the solutions.....https://www.desmos.com/calculator/exqk4ustum
