SOLUTION: solve the equation over interval [0,360) (2 cos squared theta ) + (2 cos theta) - 1 = 0

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Question 631664: solve the equation over interval [0,360)
(2 cos squared theta ) + (2 cos theta) - 1 = 0
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
solve the equation over interval [0,360)
(2 cos squared theta ) + (2 cos theta) - 1 = 0
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2cos^2x+2cosx-1=0
(2cosx-1)(cosx+1)=0
2cosx-1=0
cosx=1/2
x=60º and 300º (in quadrants I and IV where cos>0)
or
cosx-1=0
cosx=1
x=0