Estimate ${\Delta}f$ using the Linear Approximation and use a calculator to compute both the error and the percentage error.
$f(x)=\sqrt{5+x}.{\qquad}a={4}.{\qquad}{\Delta}x={-0.5}$

$\Delta{f} \approx$
With these calculations, we have determined that the square root of is approximately
The error in Linear Approximation is:
The error in percentage terms is: %