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Mark the correct alternative in the following:
If the function f(x) = 2x2 – 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) = 2x2 – kx + 5
f’(x)>0
4x-k>0
K<4x
For x=1
K<4