function [g,H] = ghban(x)
% GHBAN computes gradient & Hessian
%       of Rosenbrock's banana function
%
g = [ -400*x(1)*(x(2)-x(1)^2)-2*(1-x(1))
            200*(x(2)-x(1)^2)           ];
% 
H = [ -400*(x(2)-3*x(1)^2)+2  -400*x(1)
      -400*x(1)                200      ];