Chapter 12.1, Problem 26OE

To determine

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

  $480°$

Answer to Problem 26OE

  $120°\text{ and }-240°$

Explanation of Solution

Given:

The angle is :

  $480°$

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 $480°$ is $480°-360°=120°$

The negative angle coterminal with $480°$ is $480°-2\cdot 360°=480°-720°=-240°$