#### Answer

$2$

#### Work Step by Step

Since $sec ( x) =\frac{1}{cos(x)}$ and $cos(cos^{-1}x)=x$
The given problem can be solved as:
$sec({cos^{-1}(\frac{1}{2})})=\frac{1}{cos(cos^{-1}(\frac{1}{2}))}$
or, $\frac{1}{cos(cos^{-1}(\frac{1}{2}))}$ =$\frac{1}{\frac{1}{2}}$=2
Hence. the final answer is: $2$