Metnum3

close()
clear
clc

x=[6 8 16 49];
y=[2.5 11.35 31.01 49.9];

n=length(x);

A=[n sum(x) sum(x^2) sum(x^3); sum(x) sum(x^2) sum(x^3) sum(x^4);sum(x^2) sum(x^3) sum(x^4) sum(x^5); sum(x^3) sum(x^4)sum(x^5) sum(x^6)];
Y1=[sum(y); sum(y.*x); sum(y.*x^2); sum(y.*x^3)];

P=inv(A)*Y1
for i=1:n
    mprintf(" p%i= %f ",i,P(i))
end

z=0:0.01:50;
deff('[yk]=fun1(z)','yk=P(1)+P(2)*z+P(3)*z^2+P(4)*z^3')

plot(z,fun1(z),x,y,'o')
xlabel('x')
ylabel('y(x)')