Question

The point P(9, 12) is on the terminal side of θ. Evaluate cos θ.

Answer 1

P(9,12): For all intents and purposes, the hypotenuse is "r", the opposite side is "y", and the adjacent side is "x".

x = 9 (from the P(9,12))
y = 12 (also from the point)

Using the Pythagorean Theorem, you find out that r = 15.

Therefore, since cos θ = x/r
cos θ = 9/15 or 3/5

Answer: 3/5