1a. 2 sin^2 x - 1 = 0
Answer: x = 45°, 135°, 225°, 315° ?
3a. 2 sin^2 x + sin x = 1
5a. 2 sin^2 x + 7 sin x = 4
https://www.symbolab.com/solver/equation-calculator/%5Csin(2x)+%5Csin(x)=0,0%3C=x%3C=360
+34 
