function [e,g,w]=x_sq_lms(wini,rate);


x=-1:.1:1;
t=x.^2;

inp=[x' ones(21,1)];

w(1,:)=wini';
for i=1:21
   y(i)=inp(i,:)*w(i,:)';
   e(i)=t(i)-y(i);
   g(i,:)=-e(i)*inp(i,:);

   w(i+1,:)=w(i,:)-g(i,:)*rate;
end