# How do you plot -8+3i and find its absolute value?

Sep 19, 2016

see explanation.

#### Explanation:

From the origin, move 8 units to the left along the $\textcolor{b l u e}{\text{real axis}}$ then at right angles at this point move vertically upwards, parallel to the $\textcolor{b l u e}{\text{imaginary axis }}$for 3 units.

This is the point (-8 ,3)

Since there is a right triangle formed from

$0 \to - 8 \to 3 \to 0$ we can use Pythagoras' theorem to calculate it's magnitude, which is the distance from the origin to the point (-8 ,3)

$\Rightarrow \sqrt{{8}^{2} + {3}^{2}} = \sqrt{73} \leftarrow \text{ absolute value}$