What are cartesian sign conventions used in spherical mirror ? What is the mirror formula ?

Explanation

### Step-by-Step Solution:

**Step 1: Understanding Cartesian Sign Conventions for Spherical Mirrors**
- The Cartesian sign conventions help in determining the signs of distances in optics, particularly for spherical mirrors.
- The principal axis is divided into two parts: the horizontal axis (principal axis) and the vertical axis (perpendicular to the principal axis).

**Step 2: Assigning Signs to Distances**
- **Horizontal Axis (Principal Axis)**:
...