Chapter 12.1, Problem 23OE

To determine

Give two angles , one positive and one negative , that are coterminal with the given angle.

  $-45°$

Answer to Problem 23OE

  $315°\text{ and }-405°$

Explanation of Solution

Given:

The angle is :

  $-45°$

Formula Used:

Two angles in standard position are coterminal if their terminal sides coincide.

So, the measures of all angles coterminal with $\theta$ are:

  $\theta +n\cdot 360°$

where n is an integer.

Calculation:

The positive angle coterminal with $-45°$ is $-45°+360°=315°$

The negative angle coterminal with $-45°$ is $-45°-360°=-405°$