Question

How do you find the exact value of `cos v = sqrt(2) / 4` in quadrant IV?

Answer 1

`290.7^@`

Explanation:

Assuming that you are trying to find the angle, `v`, you would have to use your calculator to find `v` since no special triangle has side lengths `sqrt(2)` or `4`.

Using your calculator:

`cosv=sqrt(2)/4`
`v=cos^-1((sqrt2)/4)`
`v~~69.3^@`

However, this angle is in the first quadrant. To find the angle, `v`, subtract `69.3^@` from `360^@` to find the angle in the fourth quadrant:

`360^@-69.3^@`
`=290.7^@`

`:.`, angle `v` is `290.7^@`.