## Thomas' Calculus 13th Edition

Subtract 1 and divide with (-1): $\displaystyle \frac{y-1}{-1}=\frac{x^{2}}{1^{2}}+\frac{z^{2}}{1^{2}}$ We compare with Table 12.1 and, after interchanging y and z, conclude that this is an elliptical paraboloid, which opens toward the negative direction of y. The vertex is shifted 1 unit in the +y direction. The traces in xy and yz planes are parabolas. The traces in planes parallel to the xz plane are ellipses.