Matlab_Lab3_Ex2.1

clc
clear
close
k=[0:1:5];
xk=[-2,-1,3,4,7,7.5];
yk=[-1,-3,1,2,1,0.5];
x=[-2:0.01:7.5];

a=polyfit(xk,yk,length(xk)-1)
y1=polyval(a,x)

figure
plot(xk,yk,'b*',x,y1)

hold on

yk(6)=-2
b=polyfit(xk,yk,length(xk)-1)
y2=polyval(b,x)

plot(xk,yk,'r*',x,y2)