Question

Given that cos Ø= 2/5 determine the exact value of csc Ø

Answer 1

below

Explanation:

Given cos, you will have to use this to calculate sin because csc is 1/ sin

Remember cos^2 + sin^2 = 1

(2/5)^2 + sin^2 = 1

sin^2 = 21/25

sin = sqrt (21) / 5 (ignoring negative root)

csc = 1/sin = 5 / sqrt(21)