The largest volume of a cylinder that can fit into a cone with base radius r and height h is

To find the largest volume of a cylinder that fits into a cone with a base radius r and height h we need to follow these steps:
Step 1: Understand the Problem
We have a right circular cone with radius r and height h We need to find the largest possible cylinder that can fit inside this cone. The cylinder will also be right circular and its dimensions will be constrained by the cone's dimensions.
Step 2: Set Up the Equations
Let's denote:
- The radius of the cylinder as

- The height of the cylinder as

Since the cylinder is inside the cone, the top of the cylinder will form a similar triangle with the cone. The ratio of the sides of these similar triangles gives us:
![\[ (r_c)/(h - h_c) = (r)/(h) \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/j03ypo2905dp48exgf6wfmgn471bizi4za.png)
From this, we can express

![\[ r_c = (r)/(h) * (h - h_c) \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/a998qdum7dpz101iep609rgi2091nfre22.png)
Step 3: Express the Cylinder's Volume
The volume V of the cylinder is given by:
![\[ V = \pi r_c^2 h_c \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/a9fuvs7sy1547nkg6mq4nnrpx3agx0c4gz.png)
Substitute
from the earlier equation:
![\[ V = \pi \left((r)/(h) * (h - h_c)\right)^2 h_c \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/rgzrq5tuqy4taw3ant9hvco6aeznt87xk8.png)
Step 4: Maximize the Volume
To find the maximum volume, we need to differentiate this volume equation with respect to
and set the derivative equal to zero.
![\[ (dV)/(dh_c) = 0 \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/ms1ebs8c3ehykt5enlfogzhmoplh60pyjl.png)
Step 5: Solve for

By solving this equation, we can find the value of
that maximizes the volume. This involves some calculus.
Step 6: Find
and the Maximum Volume
Once we have
using the similar triangles ratio. Then, we substitute
back into the volume equation to find the maximum volume.
Now, let's perform the necessary calculations.
The critical points for the height of the cylinder
and h . The second solution, h , is not valid as it would imply a cylinder of the same height as the cone, which is not possible due to the tapering of the cone. Therefore, the valid solution is

Step 7: Calculate
and the Maximum Volume
Now, let's calculate the radius of the cylinder
and then find the maximum volume of the cylinder.
![\[ r_c = (r)/(h) * \left(h - (h)/(3)\right) = (2)/(3)r \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/vrse8m9i2ri22uaqfwg5fh1x2siy0dei5c.png)
And the maximum volume V is:
![\[ V = \pi \left( (2)/(3)r \right)^2 * (h)/(3) \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/e4wwbd3sg0yusbpw0t7k009nr50i10f6pv.png)
Let's calculate the maximum volume.
The radius
of the cylinder that maximizes its volume inside the cone is
, and the maximum volume V of this cylinder is
