## Thomas' Calculus 13th Edition

Given: $x^2+y^2+4z^2=10$ ...(1) Re-arrange as: $\dfrac{x^2}{(\sqrt{10})^2}+\dfrac{y^2}{(\sqrt{10})^2}+\dfrac{z^2}{(\sqrt{10}/2)^2}=1$ $...(2)$ Hence, the equation (2) shows a graph for An ellipsoid of revolution as shown in graph (d).