The following table gives values of the differentiable function .
x
0
1
2
3
4
5
6
7
8
9
10
  y  
  3  
  1  
  -2  
  -5  
  -4  
  2  
  -1  
  -2  
  -4  
  -6  
  -7  
Now assume that the table gives values of the continuous function y=f'(x) (instead of f(x) ). Estimate and classify critical points of the function f(x).