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

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Answer 1 · 2018-02-18T11:02:02

$1.28700221~~1.29$

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

$1.287...~~1.29$

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