# How do you find abs( 6-3i )?

Mar 3, 2018

$3 \sqrt{5}$

#### Explanation:

$\text{given a complex number "z=x+yi" then}$

•color(white)(x)|z|=|x+yi|=sqrt(x^2+y^2)

$\text{here "x=6" and } y = - 3$

$\Rightarrow | 6 - 3 i | = \sqrt{36 + 9} = \sqrt{45} = 3 \sqrt{5}$

Mar 3, 2018

$3 \sqrt{5}$

#### Explanation:

Any complex no. of the form $z = x + i y$ has $| z | = \sqrt{{x}^{2} + {y}^{2}}$
So, here x = 6, y = -3.
So we get:
$| z | = \sqrt{{6}^{2} + {\left(- 3\right)}^{2}} = \sqrt{36 + 9} = \sqrt{45} = 3 \sqrt{5}$