# How do you find the magnitude of YZ given Y(4,2) and Z(2,8)?

Feb 27, 2017

$| | Y Z | | = 2 \sqrt{10}$

#### Explanation:

Magnitude uses the principle of Pythagoras.

If I remember correctly you write magnitude of a vector as $| | Y Z | |$ or whatever letter notation is appropriate

||YZ|| = sqrt((x_2-x_1)^2+(y_2-y_1)^20

$| | Y Z | | = \sqrt{{\left(4 - 2\right)}^{2} + {\left(2 - 8\right)}^{2}}$

$| | Y Z | | = \sqrt{4 + 36} = \sqrt{40} = \sqrt{{2}^{2} \times 10}$

$| | Y Z | | = 2 \sqrt{10}$