Question

How do you evaluate using a calculator of `cos^-1(-0.3218)`?

Answer 1

`cos^-1 (-0.3218) = 108.77°`
`cos^-1 (-0.3218) = 251.23°`

Explanation:

You key it in exactly as it is written.

Use the shift/alt/2nd F key before the cos key, to use `cos^-1`

This is not the same as `1/cos`

`cos^-1` is the way of finding which angle has a cos value of `-0.3218`

`cos^-1 (-0.3218) = 108.77°`

or `cos^-1 (-0.3218) = 251.23°`