broyden2

function x = broyden2(F, x0, k)
    n = length(x0);
    B = eye(n);
    for i=1:k
        x = x0 - B*F(x0);
        delta = x - x0;
        Delta = F(x) - F(x0);
        B = B + (delta - B*Delta)*delta'*B /(delta'*B*Delta);
        x0 = x;
    end
end