Will someone please help me with these calculus questions?

Question

What is a coterminal angle of ​16⁢π/3

A. 150°

B. 240°

C. 315°

D. 1035°

For what value of θ is cscθ undefined?

A. 0°

B. 45°

C. 90°

D. 270°

Answer 1

16pi/3 has same trig functions as 4pi/3 = 150 degrees

csc0 and csc180 are undefined

cscx= 1/sinx, sinx = 0

csc0 = 1/0 which is undefined

csc180 = 1/0 which is undefined

division by zero is not allowed

try it on a calculator, you get an "error" message

1/x as x approaches zero is either +infinity or -infinity neither of which are real numbers, just limits

Answer is A) 0 degrees