SOLUTION: For which value of k will the roots of 2x^2 + kx + 1 = 0 be real?

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Question 175027: For which value of k will the roots of 2x^2 + kx + 1 = 0 be real?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
For which value of k will the roots of 2x^2 + kx + 1 = 0 be real?
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determinant = k^2 - 4*2*1 = k^2-8
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For the roots to be Real the determinant must be non-negative:
k^2-8 >= 0
k^2 >= 8
k >= 2sqrt(2) or k <= -2sqrt(2)
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Cheers,
Stan H.