SOLUTION: P(2,-3) is a point on the terminal arm of the angle θ in standard position. Calculate cos θ and give your answer to 3 decimal places.

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Question 1085574: P(2,-3) is a point on the terminal arm of the angle θ in standard position. Calculate cos θ and give your answer to 3 decimal places.
Answer by ikleyn(52852) About Me  (Show Source):
You can put this solution on YOUR website!
.
cos%28theta%29 = x%2Fsqrt%28x%5E2%2By%5E2%29 = 2%2Fsqrt%282%5E2%2B%28-3%29%5E2%29 = 2%2Fsqrt%284%2B9%29 = +/- 2%2Fsqrt%2813%29.


The point P(2,-3) is located in  Q4,  where  cos%28theta%29  is positive.


Therefore, the final answer is  cos%28theta%29 = 2%2Fsqrt%2813%29.

Solved.