1、x=-8:0.5:8;y=x;X=ones(size(y)*x;Y=y*ones(size(x);R=sqrt(X.2+Y.2)+eps;Z=sin(R)./R;mesh(X,Y,Z);colormap(hot)xlabel(x),ylabel(y),zlabel(z)1.71.11习题二2.12.22.42.5习题三3.1clf,clc,cleart=(0:18/100:18)xi=0.2:0.2:0.8;beita=sqrt(1-xi.2);sita=atan(beita./xi);y=1-exp(-t*xi).*sin(t*beita+ones(101,1)*sita)./(ones(1
2、01,1)*beita);figure(1)plot(t,y(:,1),b:,t,y(:,2),r-.,3),g-,4),kolegend(xi=0.2,xi=0.4xi=0.6xi=0.83.2clf,clearx=-50:1:50;y=-40:60;z=1./(sqrt(1-x).2+y.2)+sqrt(1+x).2+y.2);plot3(x,y,z),box onX,Y=meshgrid(x,y);Z=1./(sqrt(1-X).2+Y.2)+sqrt(1+X).2+Y.2);figure(2)mesh(X,Y,Z)figure(3)surf(Z)3.3clc;clear all;close all;t=0:pi/50:2*pi;x=sin(t);y=cos(t);z=t;plot3(x,y,z,习题四4.1 习题五5.15.45.55.65.7习题六6.26.36.4习题七7.1临界稳定不稳定(4)7.2K=367.37.4