Question

How do you use a calculator to approximate `tan^-1(-95/7)`?

Answer 1

`-85^@78`
`94^@21`

Explanation:

`tan x = - 95/7= - 13.57`
Calculator: Press "2nd", then, press "tan" to get:
arc `x = - 85^@78`
The unit circle gives another arc x that has the same tan value:
arc `x = - 85.78 + 180 = 94^@21`