Simplify the Radical Expression square root of cube root of 64

$\sqrt[2]{\sqrt[3]{64}}$

Rewrite $64$ as $4^{3}$ .

$\sqrt[2]{\sqrt[3]{4^{3}}}$

Pull terms out from under the radical.

$\sqrt[2]{4}$

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

$\sqrt[2]{2^{2}}$

Pull terms out from under the radical.

$| 2 |$

The absolute value is the distance between a number and zero. The distance between $0$ and $2$ is $2$ .

$2$