## Calculus (3rd Edition)

Elliptic paraboloid with the equation $$y= \left(\frac{x}{2}\right)^{2}+\left(\frac{z}{4}\right)^{2}.$$
The equation of the new surface after the rotation about the $x$ axis by $90^o$ will be an elliptic paraboloid with the equation $$y= \left(\frac{x}{2}\right)^{2}+\left(\frac{z}{4}\right)^{2}.$$