clc
x=6.31:0.1:7.01;
y=[316.33 330.4 344.89 359.80 375.13 390.89 407.1 423.74];
A(1,1)=sum(x.^6);
A(1,2)=sum(x.^5);
A(1,3)=sum(x.^4);
A(1,4)=sum(x.^3);
A(2,1)=A(1,2);
A(2,2)=A(1,3);
A(2,3)=A(1,4);
A(2,4)=sum(x.^2);
A(3,1)=A(1,3);
A(3,2)=A(2,3);
A(3,3)=A(2,4);
A(3,4)=sum(x);
A(4,1)=A(1,4);
A(4,2)=A(2,4);
A(4,3)=A(3,4);
A(4,4)=8;
B(1)=sum(x.^3.*y);
B(2)=sum(x.^2.*y);
B(3)=sum(x.*y);
B(4)=sum(y);
C=inv(A)*B'
xi=6.29:0.0001:6.99;

