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#?

1 Answer
Mar 4, 2018

Coordinates of #A (-(9sqrt3)/2, 9/2)#

Explanation:

#bar(OA) = 9, theta = 150^@#

A is in second quadrant.

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To find coordinates of A.

#A_x = bar(OA) cos theta = 9 * cos 150 = 9 * - cos 30 = - 9 * (sqrt3 / 2) = -(9 sqrt3)/2#

#A_y = bar(OA) sin theta = 9 * sin 150 = 9 * sin 30 = 9 * (1/2) = 9/2#