clc;
clear all;
close all;

hold on;

for x=-100:2:100
    y1=5*x^2;
    y2=40*x+5000;
    plot(x,y1,'b*');pause(0.01) %酗腚蒡 溟徜秣殛蒡 plot
    plot(x,y2,'ro');           
end                            

grid on;
legend('y1=疳襻怙朕','y2=艴桢哚',2);