How do you sketch the angle whose terminal side in standard position passes through (-8,15) and how do you find sin and cos?

1 Answer
Nghi N.
Jun 11, 2018

#sin t = 15/17#
#cos t = - 8/17#

Explanation:

The point (x = -8, y = 15), on the angle terminal side, lies in Quadrant 2. Call t the angle.
#tan t = y/x = - 15/8#
#cos^2 t = 1/(1 + tan^2 t) = 1/(1 + 225/64) = 64/289#
#cos t = +- 8/17#
Because t lies in Quadrant2, --> cos t is negative:
#cos t = - 8/17#
#sin^2 t = 1 - cos^2 t = 1 - 64/189 = 125/189#
#sin t = +- 15/17#
Because t lies in Quadrant 2, --> sin t is positive.
#sin t = 15/17#

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