# What is the complex conjugate of -2-sqrt5i?

Sep 1, 2016

$- 2 + \sqrt{5} i$.

#### Explanation:

The complex conjugate of $x + i y$ is $x - i y$.

Hence, the complex conjugate of $- 2 - i \sqrt{5}$ is

$- 2 + \sqrt{5} i$.

Sep 1, 2016

$- 2 + \sqrt{5} i$

#### Explanation:

Given a complex number $z = a \pm b i$

Then the complex conjugate $\overline{z}$ is

color(red)(|bar(ul(color(white)(a/a)color(black)(barz=a∓bi)color(white)(a/a)|)))

Note that the real part , remains unchanged while the $\textcolor{red}{\text{sign}}$ of the imaginary part reverses.

Thus the conjugate is $- 2 + \sqrt{5} i$