Question

Angle theta is in standard position. If (8,-15) is on the terminal ray of angle theta , find the values of the trigonometric function

Answer 1

The point (8,-15) lies in quadrant 4.

In quadrant 4, we draw a right triangle with legs 8 and -15 and hypotenuse 17. See picture.

I will use t for theta. My phone does not have the theta key.

sin t = -15/17

cos t = 8/17

tan t = -15/8

csc t = -17/15

sec t = 17/8

cot t = 8/-15

In quadrant 4, all trig functions are negative except for cosine and its reciprocal function secant.