SOLUTION: Find all angles, 0&#8804;&#952;<360, that satisfy the equation below, to the nearest 10th of a degree. 2cos2&#952;+9=3cos&#952;+8

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Question 966798: Find all angles, 0≤θ<360, that satisfy the equation below, to the nearest 10th of a degree.
2cos2θ+9=3cosθ+8
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Find all angles, 0≤θ<360, that satisfy the equation below, to the nearest 10th of a degree.
2cos2θ+9=3cosθ+8
***
2cos%282x%29%2B9=3cosx%2B8
2%28cos%5E2%28x%29-sin%5E2%28x%29%29-3cosx%2B1=0
2%28cos%5E2%28x%29%29-%281-cos%5E2%28x%29%29-3cosx%2B1=0
2cos%5E2%28x%29-2%2B2cos%5E2%28x%29-3cosx%2B1=0
4cos%5E2%28x%29-3cosx-1=0
(4cosx+1)(cosx-1)=0
..
4cosx+1=0
cosx=-1/4
x=104.5˚, 255.5˚
or
cosx+1=0
cosx=-1
x=180˚