If I be an open interval containing the point x. (x0) and suppose that the function f:I->R has two derivatives. Prove that
lim as h->0 (f(x.+h) - 2f(x.) + f(x.-h))/ h^2 = f"(x.)© BrainMass Inc. brainmass.com March 4, 2021, 5:45 pm ad1c9bdddf
By forward difference
f"(x.)= (f'(x+h)-f'(x))/h ...
The expert provides a proof using forward difference.