SOLUTION: Solve 2cos2x + cosx − 1 = 0 for x over the interval [0, 2 3.14 ).

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Question 939140: Solve 2cos2x + cosx − 1 = 0 for x over the interval [0, 2 3.14 ).
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
2cos^2x + cosx - 1 = 0
(2cosx - 1)(cosx + 1)= 0
cosx = 1/2 x = pi/3, 5pi/3
cosx = -1 , x = pi
(cosx, sinx) Summary Unit Circle
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