Find the moment of inertia of a cylinder of mass `M`, radius `R` and length `L` about an axis passing through its centre and perpendicular to its symmetry axis. Do this by integrating an elemental disc along the length of the cylinder.

Explanation

To find the moment of inertia of a cylinder of mass \( M \), radius \( R \), and length \( L \) about an axis passing through its center and perpendicular to its symmetry axis, we will use the method of integration by considering elemental discs along the length of the cylinder.

### Step-by-Step Solution:

1. **Visualize the Cylinder**:
- Imagine a cylinder of radius \( R \) and length \( L \). The axis of rotation is perpendicular to the symmetry axis and passes through the center of the cylinder.

2. **Elemental Disk**:
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