Let f be a function [0 ,1] ->[0,1] and
|f(x)-f(z)| <= |x-z| x,z in [0,1].
I need to proove that the sequence
x_n+1 = 1/2 * [x_n + f(x_n)], n in N
converges to a fixed point of f.
I wasn't quite seeing it. I was hoping I could get one of you'all to talk me into it.
It was rather weak to rely on "non-increasing". Since the sequence would quikly leave the Domain if it had to stick with equality, it would be stronger to state "decreasing", but that remains only as convincing as the Harmonic example.
Well, Mark84, what are your thoughts? What is it about that slope that ensures convergence?