function fprime = fdiff(f, x, h)
%FDIFF Forward finite difference derivative.
%   FPRIME = FDIFF(F, X, H) computes the derivative FPRIME of the
%   function F at all values in X using a step size of H.
 
fplus = f(x + h);
fx = f(x);
fprime = (fplus - fx) / h;
