Question

How do you evaluate `cos(arcsin(-1/4))`?

Answer 1

Evaluate `cos (arcsin (-1/4))`

Explanation:

Calculator gives:
`sin x = - 1/4 = - 0.25`--> Calculator gives:

a. `x = - 14.48` deg
Trig unit circle gives another arc x that has the same sine value:
b. `x = 180 + 14.48 = 194.48` deg

Answers:
cos (-14.48) = cos (14.48) = 0.97
cos (194.48) = - 0.97