# What is the complex conjugate of the square root of -7?

Sep 6, 2015

I suppose: $- \sqrt{7} i$ and $+ \sqrt{7} i$

#### Explanation:

$\sqrt{- 7} = \sqrt{- 1 \cdot 7} = \sqrt{7} i$
where $\sqrt{- 1} = i$ is the Imaginary Unit.
$z = 0 + \sqrt{7} i$
$z = 0 + \sqrt{7} i = + \sqrt{7} i$
$z = 0 - \sqrt{7} i - \sqrt{7} i$