How do you simplify: the square root of -169?

Aug 10, 2015

You may start by observing that $169 = {13}^{2}$
$\sqrt{- 169} = \sqrt{\left(- 1\right) \times \left(169\right)} = \sqrt{- 1} \cdot \sqrt{169} = \sqrt{- 1} \cdot \sqrt{{13}^{2}} = i \cdot 13 = 13 i$