Question

How do you evaluate cos [csc (-2.345)] to four significant digits using a calculator set in radian mode?

Answer 1

Find `cos (csc (-2.345))`

Explanation:

`csc x = 1/sin x = -2.345` --> `sin x = 1/-2.345 = - 0.4264`

->`x = 25.2417` and `x = 180 - 25.2417 = 154.7582`

`a. cos (25.2417) = - 0.9045`

`b. cos (154.7582) = - 0.9045`