The volume of the largest right circular cone that you can inscribe in a sphere of radius r equals _______

(Your answer will be an expression in r.)

see related questions below. In particular,

http://www.jiskha.com/display.cgi?id=1318801288

To find the volume of the largest right circular cone that can be inscribed in a sphere of radius r, we can use the concept of similar triangles.

Consider the following diagram:

```
/\
/ \
/ \
/______\
```

Let's assume that the sphere is centered at point O and the cone is inscribed within it such that the apex of the cone coincides with the center of the sphere.

To find the volume of the cone, we need to determine its radius and height.

Since the cone is inscribed in the sphere, the radius of the sphere is equal to the slant height (l) of the cone. The slant height is the distance from the vertex of the cone to any point on the circular base.

We can see that the diameter of the circular base of the cone is equal to the diameter of the sphere (2r). Therefore, the radius (R) of the cone's base is equal to half the diameter of the sphere, which is r.

Now, let's consider the right triangle formed by the height (h), the slant height (l), and the radius of the cone's base (R).

By the Pythagorean theorem, we have:

(R)^2 + (h)^2 = (l)^2

Substituting the values, we get:

(r)^2 + (h)^2 = (r)^2

Simplifying the equation, we find:

(h)^2 = 0

This implies that the height (h) of the cone is zero. Therefore, the cone is degenerate, meaning that it is essentially a flat disk.

In other words, it is not possible to inscribe a well-defined cone inside a sphere such that the height is greater than zero. The largest possible right circular cone that can be inscribed in a sphere has a height of zero.

Hence, the volume of the largest right circular cone that can be inscribed in a sphere of radius r is zero.