Answer
$\approx1.23.$
Work Step by Step
I know that $\sec x=\frac{1}{\cos(x)}$, hence $\sec^{-1}x=cos^{-1} \frac{1}{x}$.
I use a calculator in radian mode and then round the result, hence: $\sec^{-1}{(3)}=\cos^{-1}{\frac{1}{3}}=1.2310\approx1.23.$
