Find the exact value of each trigonometric expression, if it exists.

Question

1. 2.

Answer 1

sin(-pi/4) = -1

cos^-1(sin(-pi/4)) = cos^-1(-1) = pi

answer to 1. is pi

cot(19pi/3) = cot(6 1/3 pi) = cot(pi/3) = cot(180/3) = cot(60 degrees) = 1/sqr3 = (1/3)sqr3

answer to 2. is cot(19pi/3) = (1/3)sqr3