Find the critical numbers (calculus)?

Question

Find the critical numbers of 
f(x)= |x^3 - 3 x^2 + 2| 

Answer 1

The Function is f(x) = |x³ - 3x² + 2|

Let us Consider u = x³ - 3x² + 2

Now we can write the function as

Differentiate f(x) with respect to x.

Now to find the Critical Points f'(x) = 0.

If 3x = 0 then x = 0,

then roots of the Equation are 1, 2, 2.73 and -0.73.

Therefore the critical points are -0.73, 0, 1, 2 and 2.73.