用Matlab的数值计算方法编程,在同一幅图中画出几个函数图象.

clear all
clc
x=0:0.1:5*pi;
y1=10/sqrt(1-0.5^2)*exp(-0.5*x).*sin(5*x);
y2=10/sqrt(1-0.5^2)*exp(-0.5*x);
y3=-10/sqrt(1-0.5^2)*exp(-0.5*x)
plot(x,y1,'r-',x,y2,'g-.',x,y3,'k')
title('stuid+stuname');
xlabel('振荡时间x');
ylabel('振荡函数幅度值');
axis([0,14,-12,12]);
text(0.5*pi,10/sqrt(1-0.5^2)*exp(-0.5*0.5*pi).*sin(5*0.5*pi),'曲线f1');
text(0.3*pi,-10/sqrt(1-0.5^2)*exp(-0.5*0.3*pi),'曲线f1的包络')