Q14 of 105 Page 17

Mark the correct alternative in the following:

Function f(x) = x3– 27x +5 is monotonically increasing when


Formula:- (i) 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)


Given:-


f(x)= x3– 27x +5


=3x2– 27=f’(x)


for increasing function f’(x)>0


3x2– 27>0


(x+3)(x-3)>0


|x|>3

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