clc

x0 = [1 2 4 6 8 10];
y0 = [6 6 4 2 0 0];
x = 0:0.2:11
hold on

plot(x0, y0, 'g*')

w2 = polyfit(x0, y0, 2);
f2 = polyval(w2, x);
plot(x, f2, 'r');

w3 = polyfit(x0, y0, 3);
f3 = polyval(w3, x);
plot(x, f3, 'b');
hold off;
y=f_lagrange(x0,y0,x);
plot(x,y,'c');