# How do you find abs( -3-5i )?

Jul 28, 2016

$| - 3 - 5 i | = \sqrt{34}$

#### Explanation:

The modulus of a complex number $a + b i$, denoted $| a + b i |$, is given by

$| a + b i | = \sqrt{{a}^{2} + {b}^{2}}$

and represents the distance of that number from the origin on the complex plane.

In this case, then, we have

$| - 3 - 5 i | = | - 3 + \left(- 5\right) i | = \sqrt{{\left(- 3\right)}^{2} + {\left(- 5\right)}^{3}} = \sqrt{34}$