Thread: Fundamental Theorem of calculus

1. The problem statement, all variables and given/known data

Find a function f : [-1,1] ---> R such that f satisfies the following properties:

a) f is continuous
b) f is restricted to (-1,1) is differentiable
c) its derivative f' is not differentiable on (-1,1)

2. Relevant equations


3. The attempt at a solution
I kinda think that the mean value theorem and Theorem 2 of the fundamentals f(x)dx = F(b)-F(a) got some link but I can't seem to get it. I do understand that for f'' not to exist, x should be undefined on the (-1,1). Please help.

read somewhere that a hint would be to begin with an absolute value and use f(x)dx = F(b)-F(a) (fundamental theorem of calc prep 2) repeatedly.. but still puzzled