Answer
Horizontal Cylinder(along Y-axis) in 3D- system with radius “3”.
Work Step by Step
Given equation
x^2+z^2=9
This equation represent the circle with radius “r” x^2+y^2=r^2 in xy- Plane . Now , we discuss in three-dimensional system (xyz-Plane). According given equation f(x,z)=k while k=y here., SO given equation make a horizontal Cylinder(along Y-axis) in 3D- system with radius “3”. Graph of given equation as