Question
Find the maximum and minimum values, if any, of the following function without using the derivatives:
9x2 – 12x + 4
Solution
Let f (x) = 9x2 – 12x + 4 = (3 x – 2)2 ≥ 0
∴ f (x) ≥ 0 ∀ a ∊ R
Minimum value of f (x) is 0 and is obtained at 
There is no maximum value of the function.
