Simplify square root of 9* square root of 8

$\sqrt{9} \cdot \sqrt{8}$

Rewrite $9$ as $3^{2}$ .

$\sqrt{3^{2}} \cdot \sqrt{8}$

Pull terms out from under the radical, assuming positive real numbers.

$3 \cdot \sqrt{8}$

Rewrite $8$ as $2^{2} \cdot 2$ .

Factor $4$ out of $8$ .

$3 \cdot \sqrt{4 (2)}$

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

$3 \cdot \sqrt{2^{2} \cdot 2}$

Pull terms out from under the radical.

$3 \cdot (2 \sqrt{2})$

Multiply $2$ by $3$ .

$6 \sqrt{2}$

The result can be shown in multiple forms.

Exact Form:

$6 \sqrt{2}$

Decimal Form:

$8.48528137 \dots$