x=[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]y=[1.2, 3, 4, 4, 5, 4.7, 5, 5.2, 6, 7.2]p2=polyfit(x,y,2)p3=polyfit(x,y,3)y2=polyval(p2,x)y3=polyval(p3,x)hold onplot(x,y2,"r")plot(x,y3,"b")plot(x,y,"*")