Chapter 4.1, Problem 40E

To determine

To state: the number of complex roots of $a^2-81=0$ and then find the roots and graph.

Answer to Problem 40E

There aretwo roots. The roots of the equation are $a=-9\text{ and }9$ .

  

Explanation of Solution

Given information: $a^2-81=0$

Calculation:

Since, this is a second degree equation, there should be two roots. After solving for a, the roots are $x=-9\text{ and 9}$

  $\begin{array}{l}{a}^2-81=0\\ a^2=81\\ a=-9,9\end{array}$

The graph