find the value of k for which the inequality x^2-2(4k-1)x+15k^2-2k-7>=0,for all x

Asked by Aravindh Nandha Raj s | 3rd Jun, 2013, 05:37: PM

Expert Answer:

Given is a quadratic xpression which is greater than equal to 0, thus, D = b^2-4ac <0

(2(4k-1))^2 - 4(15k^2-2k-7)<0

k^2-6k+8<0

(k-2)(k-4)<0

Thus, 2

or, k=3

Answered by  | 8th Jun, 2013, 10:49: PM

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