plot%E2%8C%8A(%E2%8C%8Ax%2B%E2%88%9A(3)y%2B1%E2%8C%8B%2B%E2%8C%8A-x%2B%E2%88%9A(3)y%2B1%E2%8C%8B)%2F3%E2%8C%8B x%3D-1.5..1.5 y%3D-1.5..1.5