trigonometric functions

Question 1

if sin is at 0, 180°, 360°, π, or 2π, what is it worth?

Answer 1

0

Question 2

if sin is at 90°, 270°, π/2, or 3π/2, what is it worth?

Answer 2

1 or -1

Question 3

if sin is at 60°, 120°, 240°, 300°, π/3, 2π/3, 4π/3, or 5π/3, what is it worth?

Answer 3

√3/2 or -√3/2

Question 4

if sin is at 45°, 135°, 225°, 315°, π/4,

Answer 4

√2/2 or -√2/2