Question

For what x-value(s) does sin(x) = -1?
A. -270°, -90°, 90°, and 270°
B. -270°, -90°, 0°, 90°, and 270°
C. -90 and 270°
D. -270° and 90°

Answer 1

C. -90 and 270

Answer 2

sin= y/r

-90= (0, -1) 270= ( 0,-1)
y/r= -1/1=-1 y/r= -1/1 = -1