Can someone help me with this?? Find the critical points

Question

for the function f(x)=((∣x∣)/(x^2+9))+9?

Answer 1

The function is

Differentiate with respect to x.

To find the critical numbers f'(x) = 0 and f'(x) does not exist.

The function does not exist when .

The imaginary numbers are negligible, the critical numbers are x = 0, x = 3 and x = -3.

The critical points are .