12.4k views
1 vote
Identify the surface whose equation is given. rho = sin(θ) sin(φ)

User Phil Poore
by
6.7k points

1 Answer

3 votes

Explanation:

Given;

  • The equation of the surface is, ρ = sin(θ) sin(φ)

The spherical and Cartesian coordinates are related by the equations,

x = ρ sin(φ) cos(θ)

y = ρ sin(φ) sin(θ)

z = ρ cos(φ)

Here, x, y and z represent the coordinates of the center of the sphere on x, y and z axes respectively.

Now, multiply the given surface equation by ρ.

ρ² = ρsin(θ) sin(φ)

We have, ρ² = x² + y² + z².

Substitute this value in above equation and also replace the RHS by y coordinate.

x² + y² + z² = y

Now, simplify the above equation.

x² + y² - y + z² = 0

x² + y² - 2y½ + (1/2)² + z² = (1/2)²

x² + (y - 1/2)² + z² = (1/2)² ...(1)

The general form of equation of sphere is,

(x - a)² + (y - b)² + (z - c)² = r²

Here, a, b, c are the coordinates of the center of the sphere on x, y, z axes respectively and r is the radius of the sphere.

Compare equation (1) with the general form of equation of sphere. Therefore we get,

  • a = 0
  • b = 1/2
  • c = 0
  • r = 1/2

Therefore, the radius of the sphere is 1/2 and center of sphere is at (0, 1/2, 0).

Thus, The given equation represents - a sphere of radius 1/2 centers at (0, 1/2, 0).

User Archie
by
6.7k points