Final answer:
In spherical coordinates, an equation of the form r = f(θ, ϕ) represents a surface.
Step-by-step explanation:
In spherical coordinates, an equation of the form r = f(θ, ϕ) represents a surface. The variable r is the radial coordinate, θ is the polar angle, and ϕ is the azimuthal angle. To find a specific equation, we need more information about the surface.