t5_7.asv

The matlab source code.It s very usefulness.

subplot(1,2,1);
x1=-5:5;y1=-5:5;
[x1,y1]=meshgrid(x1,y1);
z1=5+(x1+y1)-(x1+y1);
mesh(x1,y1,z1);
title('第一题');
xlabel('X');ylabel('Y');zlabel('Z');
grid on;
subplot(1,2,2);
[x,y]=meshgrid(-3:0.1:3);
z=-5./(1+x.*x+y.*y);
mesh(x,y,z);
title('第二题');
xlabel('X');ylabel('Y');zlabel('Z');
grid on;