Answer:
Step-by-step explanation:
-2/3 < y < 0
y = Asin(x)
Edit*
There's a node (y=0) at pi for sine wave. At 3/2pi will be the min. So range goes from -2/3 to 0
x-8°+20°= 90°
=>x+12°=90°
=>x=90°-12°
=>x= 78°
