Question

How do you use a calculator to approximate `arccos0.28`?

Answer 1

`1.28700221~~1.29`

Explanation:

In a calculator, type in `cos^-1(0.28)`, or enter `0.28` and then press the `cos^-1` button.

Note that this depends from calculator to calculator.

When you are finished, press enter, and you should get something like

`1.287...~~1.29`