How is $150^{\circ}$ $150^@$ related to $30^{\circ}$ $30^@$ on the unit circle?

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Answer 1 · 2018-03-13T21:27:43

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

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
$cos(30˚) = -cos(150˚)$

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