Question

which choices are equivalent to the expression below? check all that apply. rad -9 A.3i B.-3 C.irad-9 D.-rad9​

Answer 1

Given:

Consider the expression is:

$\sqrt{-9}$

To find:

The equivalent expression.

Solution:

We have,

$\sqrt{-9}$

It can be written as:

$\sqrt{-9}=\sqrt{-1\times 9}$

$\sqrt{-9}=\sqrt{-1}\times \sqrt{9}$

$\sqrt{-9}=i\times 3$                 $[\because \sqrt{-1}=i]$

$\sqrt{-9}=3i$

The expression $3i$ is equivalent to the given expression.

Therefore, the correct option is A.