# How do you simplify sqrt(-8/9)?

It is

$\sqrt{- \frac{8}{9}} = \sqrt{{i}^{2} \cdot {2}^{3} / {3}^{2}} = \frac{2}{3} \cdot i \cdot \sqrt{2}$

where $i$ is the complex unit with ${i}^{2} = - 1$