Homework Statement
consider two functions:ψ(x) which is eqaul to zero at a,that is ψ(a)=0
and f(x)=H(x-a)*β(x)+(1-H(x-a))*γ(x)
where H(x-a) is the heaviside step function and β(x),γ(x) is the continuous function.
it seems that the derivative of f(x) is not exist.
the question is whether...