SOLUTION: Solve the given equation over the interval [0,2pi): 2cos^2x+cos x+15=0

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Question 963180: Solve the given equation over the interval [0,2pi): 2cos^2x+cos x+15=0
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Substitute u=cos%28x%29
2u%5E2%2Bu%2B15=0
Graphing the equation,
graph%28300%2C300%2C-10%2C10%2C-2%2C18%2C2x%5E2%2Bx%2B15%29
As you can see the graph never crosses the x-axis.
There are no solutions.