Question
Prove that the function f(x) = x3 – 3x2 + 3x – 100 is increasing on R.
Solution
Here f(x) = x3 – 3x2 + 3x – 100
Df = R
f ' (x) = 3x2 – 6 x + 3 = 3 (x2 – 2 x + 1) = 3 (x – 1)2 ≥ 0 ∀ x ∊ R
∴ f (x) is increasing on R.
