Hello,
I'm only curious and this post has nothing to do with Samantha's problem.
If I take the definition I get:
1. c belongs to the domain
2. A critical number exists if f'(x) doesn't exist.
In my opinion this takes place with functions like:
1.
2. exists
3. f'(0) doesn't exist. Thus x = 0 is a critical number
Do I get this right?