Question

Use the unit circle to find cos (-270°)

Answer 1

B.

Explanation:

0

Answer 2

`\cos (-270\degree)=0`.

Explanation:

We want to find the value of
`\cos (-270\degree)`.

Note that;

`\cos (-\theta)=\cos (\theta)`

This implies that;

`\cos (-270\degree)=\cos (270 \degree)`

Also 270 degrees is a quadrantal angle.

On the unit circle,
`\cos (270\degree)` is the x-coordinate of the point
`(0,-1)`

Hence,
`\cos (-270\degree)=0`.