function [xn,erro,k]=mis(g,x0,tol,maxiter)
k=1
erro(1)=tol+1
while erro>tol & k<maxiter 
        xn=feval ('g',x0);
          erro(k)=abs (xn-x0)/abs (xn);
    x0=xn;
    k=k+1;
end
return