Mark the correct A. x < –3

B. |x| > 3

C. x ≤ –3

D. |x| ≥ 3

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