Question

How do you use a calculator to approximate `arccos(-0.7)`?

Answer 1

`x = +- 134^@42`

Explanation:

Use calculator
cos x = (- 0.7)
Press --> - 0.7 --> 2nd --> cos --> `x = 134^@42`
Unit circle gives another x that has the same cos value -->
`x = - 134^@42`
Answers: `x = +- 134^@42`