Mark (√) against the correct answer in the following: The function is increasing when

Question

Philoid · Accepted Answer

Given:

f(x) = x³-27x+8.

f’(x) = 3x²-27x = 0

f’(x) = 3(x²-9) =0

f’(x) = 3(x-3)(x+3) = 0

x = 3 or x =-3

for x>3 f(x) is increasing

for x<-3 f(x) is increasing

∴ for |x|>3 f(x) is increasing.