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Find the largest integer k such that the roots of 2x^2 + kx + 5 are rational numbers.

 Feb 27, 2021
 #1
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Find k so the vertex just touches the x axis in this bowl shaped parabola

for this to happen the discriminant must = 0

 

k^2 - 4(2)(5) = 0      k = sqrt 40

 Feb 27, 2021

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