Question

How is `150^@` related to `30^@` on the unit circle?

Answer 1

150˚ is the mirror image of 30˚ across the x-axis if that makes sense...

Explanation:

If you look at the unit circle you can see that both angles are rotated by 60˚ from 90˚ (the x-axis) but in opposite directions.

`30˚ = 90˚ - 60˚`
`150˚ = 90˚ + 60˚`

This means that
`sin(30˚)= sin(150˚)`
and
`cos(30˚) = -cos(150˚)`