ans=[0;0;0;];
x(1)=2.1;
y(1)=13.2;
x(2)=4.9;
y(2)=65;
x(3)=1.4;
y(3)=6.5;
x(4)=-2.4;
y(4)=-1.1;
for j =1:1000
for i =1:4
y0(i)=x(i)^2*ans(1)+x(i)*ans(2)+ans(3);
end
for i=1:4
g(i,1)=x(i)^2;
g(i,2)=x(i);
g(i,3)=1;
end
for i=1:4
dy(i)=y(i)-y0(i);
end
dans=inv(g'*g)*g'*dy'
ans=ans+dans
error=norm(dans)
end