Simplify square root of -28

$\sqrt{- 28}$

Step 1

Rewrite $- 28$ as $- 1 (28)$ .

$\sqrt{- 1 (28)}$

Step 2

Rewrite $\sqrt{- 1 (28)}$ as $\sqrt{- 1} \cdot \sqrt{28}$ .

$\sqrt{- 1} \cdot \sqrt{28}$

Step 3

Rewrite $\sqrt{- 1}$ as $i$ .

$i \cdot \sqrt{28}$

Step 4

Rewrite $28$ as $2^{2} \cdot 7$ .

Factor $4$ out of $28$ .

$i \cdot \sqrt{4 (7)}$

Rewrite $4$ as $2^{2}$ .

$i \cdot \sqrt{2^{2} \cdot 7}$

Step 5

Pull terms out from under the radical.

$i \cdot (2 \sqrt{7})$

Step 6

Move $2$ to the left of $i$ .

$2 i \sqrt{7}$