f is a function from [a,b] to .
We suppose :
1) Show that f is the function null from .
I think that we must use Taylor's inegalities which say that (I don't know if it's the same name ...) :
where M majors from [a,b].
so, here, we have:
howerver we can take
so we have:
and I have no idea to keep on the demonstration.
do you understand what I said ?