# How do you write in simplest radical form the coordinates of point A if A is on the terminal side of angle in standard position whose degree measure is theta: OA=9, theta=150^circ?

Mar 4, 2018

Coordinates of $A \left(- \frac{9 \sqrt{3}}{2} , \frac{9}{2}\right)$

#### Explanation:

$\overline{O A} = 9 , \theta = {150}^{\circ}$

${A}_{x} = \overline{O A} \cos \theta = 9 \cdot \cos 150 = 9 \cdot - \cos 30 = - 9 \cdot \left(\frac{\sqrt{3}}{2}\right) = - \frac{9 \sqrt{3}}{2}$
${A}_{y} = \overline{O A} \sin \theta = 9 \cdot \sin 150 = 9 \cdot \sin 30 = 9 \cdot \left(\frac{1}{2}\right) = \frac{9}{2}$