function [f,g] = f53(n,x)
%F53 function and gradient f5 for c=100.CMSC 764 HW1.
%   [f,g] = f53(n,x) gives the function value f and 
%   gradient g for the vector x of dimension n for test
%   problem f5.
%
%   See also Hf53.

%  Geping Liu 09-21-06

f = (x(1,:) - 1) .^2 + (x(2,:) - 1) .^2 + 100 .* (x(1,:) .^2 + x(2,:) .^2 - .25) .^2;
g = [ 2 .* x(1,:) - 2 + 400 .* (x(1,:) .^2 + x(2,:) .^2 - 1/4) .* x(1,:)
      2 .* x(2,:) - 2 + 400 .* (x(1,:) .^2 + x(2,:) .^2 - 1/4) .* x(2,:)];