# How do you find abs( -5 - 4i )?

Sep 6, 2016

$\sqrt{41}$

#### Explanation:

Given a complex number z = x + yi , then it's $\textcolor{b l u e}{\text{modulus ( magnitude )}}$ is found using Pythagoras' theorem.

$\textcolor{\mathmr{and} a n \ge}{\text{Reminder }} \textcolor{red}{| \overline{\underline{\textcolor{w h i t e}{\frac{a}{a}} \textcolor{b l a c k}{| x + y i | = \sqrt{{x}^{2} + {y}^{2}}} \textcolor{w h i t e}{\frac{a}{a}} |}}}$

here x = - 5 and y = -4

|-5-4i|=sqrt((-5)^2+(-4)^2)=sqrt(25+16)=sqrt41≈6.403" units"