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Cos x+ 2cosx + Sinx=0 solve the equation for the interval [0,2pi]

User Nelli
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1 Answer

1 vote
cos²(x) + 2cos(x) + sin²(x) = 0
Note: cos²(x) + sin²(x) = 1
2cos(x) + 1 = 0
2cos(x) = -1
cos(x) =
- (1)/(2)
120 degrees and 240 degrees →
(2)/(3) \pi and
(4)/(3) \pi
User Reggaemahn
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6.0k points