SOLUTION: Solve cos2x = -cosx over the interval 0 ≤ x < 2pi

SOLUTION: Solve cos2x = -cosx over the interval 0 ≤ x < 2pi

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Question 1138018: Solve cos2x = -cosx over the interval 0 ≤ x < 2pi
Answer by MathLover1(20849) (Show Source): You can put this solution on YOUR website!
for the interval
..........use the following identity :

.......let

solutions:
if =>
if=>

since , we have
or

if , and , then
if , and, than ,

combine all solutions: , ,

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