How do you find abs( 2 − i )?

Aug 23, 2016

$| 2 - i | = \sqrt{5}$

Explanation:

The absolute value of complex number $a + b i$ is written as $| a + b i |$ and is equivalent to $\sqrt{{a}^{2} + {b}^{2}}$.

Hence $| 2 - i |$

= $\sqrt{{2}^{2} + {\left(- 1\right)}^{2}}$

= $\sqrt{4 + 1}$

= $\sqrt{5}$