SOLUTION: Solve the equation on [0,2pie). Approximate the solution(s) to four decimal places, if necessary. 2cos^2x-cosx-1=0

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Question 138612: Solve the equation on [0,2pie). Approximate the solution(s) to four decimal places, if necessary. 2cos^2x-cosx-1=0
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Solve the equation on [0,2pie). Approximate the solution(s) to four decimal places, if necessary. 2cos^2x-cosx-1=0
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Factor to get:
(2cosx + 1)(cosx - 1) = 0
cosx = -1/2 or cosx = 1
x = pi/3 radians or -pi/3 radians or 0 radians
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Cheers,
Stan H.