Expressing an Imaginary Number in Standard Form

Express $\sqrt{−9}$ in standard form.

Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.

Solution
$\begin{matrix} \sqrt{−9} & = & \sqrt{9} \sqrt{−1} \\ = & 3 i \end{matrix}$

In standard form, this is $0 + 3 i .$

Your turn

The book's Try It right after this example: same idea, new numbers. Only the answer is given.

Express $\sqrt{−24}$ in standard form.

How did it go?