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5

Mark the correct alternative in the following:

If the function f(x) = 2x^{2} – kx + 5 is increasing on [1, 2], then k lies in the interval.

Formula:- The necessary and sufficient condition for differentiable function defined on (a,b) to be strictly increasing on (a,b) is that f’(x)>0 for all x(a,b)

f(x) = 2x^{2} – kx + 5

f^{’}(x)>0

4x-k>0

K<4x

For x=1

K<4

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