x = 0.5;
y = 0.5;
for i = 1:2
    J = [2*x,2*y;3*x^2,-1];
    F = [x^2+y^2-1;x^3-y-2];
    H = -J\F;
    x = x+H(1);
    y = y+H(2);
    disp(H)
    disp([x,y])
end