# How do you find abs(0 - 4i )?

Mar 27, 2016

4

#### Explanation:

Given a complex number x + iy , then it's magnitude is found
using ' Pythagoras' theorem' , as follows.

| x + iy | = $\sqrt{{x}^{2} + {y}^{2}}$

$\Rightarrow | 0 - 4 i | = \sqrt{{0}^{2} + {\left(- 4\right)}^{2}} = \sqrt{16} = 4$