Final answer:
The equation z = 6 - y^2 represents a parabolic cylinder because it describes a cylindrical shape where the z-coordinate varies in a parabolic relationship to the y-coordinate, independent of x.
Step-by-step explanation:
The given equation z = 6 - y2 represents a surface where z varies as a function of y only, and x can take any value without changing the surface.
This implies that for each value of y, there is a corresponding value of z and x is unrestricted. This creates lines parallel to the x-axis for each y and z coordinate, forming a cylindrical shape.
However, since z is dependent on y in a quadratic form and there i
s no x dependency, this surface is not a standard cylinder, but instead a type of cylinder called a parabolic cylinder. The fact that z decreases as y increases, in a squared relationship, without depending on x makes it clearly parabolic in nature.