Chapter 12.5, Problem 4MRE

To determine

To Evaluate: The given expression $\sqrt{z^2+4xy}$ if $x=1,y=8,\text{and }z=-9$

Answer to Problem 4MRE

The required solution is $\pm \sqrt{113}$ .

Explanation of Solution

Given information:

  $\sqrt{z^2+4xy}$

  $x=1,y=8,\text{and }z=-9$

Calculation:

  $\sqrt{z^2+4xy}$

Substituting the known value

  $\begin{array}{l}=\sqrt{{\left(-9\right)}^2+4\cdot 1\cdot \left(8\right)}\\ =\sqrt{81+32}\\ =\pm \sqrt{113}\end{array}$