Chapter 11.7, Problem 4QCE

Classify each surface as an ellipsoid, hyperboloid of one sheet, hyperboloid of two sheets, elliptic cone, elliptic paraboloid, or hyperbolic paraboloid.

$\begin{array}{l}\left(\text{a}\right)\frac{x^2}{36}+\frac{y^2}{25}-z=0\\ \left(\text{b}\right)\frac{x^2}{36}+\frac{y^2}{25}+z^2=1\\ \left(\text{c}\right)\frac{x^2}{36}-\frac{y^2}{25}+z=0\\ \left(\text{d}\right)\frac{x^2}{36}+\frac{y^2}{25}-z^2=1\\ \left(\text{e}\right)\frac{x^2}{36}+\frac{y^2}{25}-z^2=0\\ \left(\text{f}\right)z^2-\frac{x^2}{36}-\frac{y^2}{25}=1\end{array}$