Question 735476: verify all solutions to the equations in the interval [0,2pie)
2sin^2x=2+cosx
Answer by lwsshak3(11628)   (Show Source):
You can put this solution on YOUR website! verify all solutions to the equations in the interval [0,2pie)
2sin^2x=2+cosx
2(1-cos^2x)=2+cosx
2-2cos^2x=2+cosx
2cos^2x+cosx=0
cosx(2cosx+1)=0
..
cosx=0
x=1
..
2cosx+1=0
cosx=-1/2
x=2π/3, 4π/3 (in Q2 and Q3 where cos<0)
..
solutions: x=1, 2π/3, 4π/3
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