SOLUTION: Find all solutions of 2cos2 x + 3 cos x + 1 = 0 where x is in radians between 0 and 2pi.

Question 265830: Find all solutions of 2cos2 x + 3 cos x + 1 = 0 where x is in radians
between 0 and 2pi.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Find all solutions of 2cos^2 (x) + 3 cos (x) + 1 = 0 where x is in radians
between 0 and 2pi.
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Factor:
(2cos(x) +1)(cos(x) + 1) = 0
cos(x) = -1/2 or cos(x) = -1
x = arccos(-1/2) or x = arccos(-1)
x = (2/3)pi or (4/3)pi OR x = pi
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Cheers,
Stan H.
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