% plot1.m 96/07/14
%
% Program to plot y versus f(x,y) = 4-.5(x-2)^2-.5(y-2)^2
% for x=2.

%   hold off;
    colormap('white');
    x=2; 
    y=(1:.1:3);
    z=4-.5*(y-2).^2;
    plot(y,z,'w-');
    hold on;
    axis([-.25 4.25 0 4.5]);
    plot([1 1],[0 3.5],'w--');
    plot([3 3],[0 3.5],'w--');
    xlabel('y');
    ylabel('z');
    text(3,4,'z=f(x,y)')

    hold off;

