I am stuck with this problem. The quadric surface $xy=z^2+z$ is given to me, and I have to find the gaussian curvature in $(0,0,0)$. Is there an easy way? I have tried parametrizing it but I was unable to do that.
Can I go to the projective space, and choose $z+w=0$ as the plan at infinity? Doing that I can find an easy parametrization, but I am not sure the gaussian curvature remains the same.
Thanks