QUICK HELP ?!?!?

Question

following is the work for using the unit circle in find the exact value of sim 17π/3

a)which step has the first error?

b)explain the error

1)find the coterminal angle

17π/3-2π=5π/3

2) using the unit circle, the point at 5π/3 is (1/2,-sqart3/2)

3)because sim is the y value, sin17π/3=-sqart/2

Answer 1

(17π / 3) - 2π

(17π / 3) - (6π / 3)

11π / 3