A convex mirror forms the image of an object placed at a distance 40 cm in front of mirror, at distance 10 cm Find the focal length of mirror.

Explanation

To find the focal length of a convex mirror given the object distance and image distance, we can follow these steps:

### Step 1: Identify the given values
- Object distance (U) = -40 cm (negative because the object is in front of the mirror)
- Image distance (V) = +10 cm (positive because the image is virtual and formed behind the mirror)

### Step 2: Use the mirror formula
The mirror formula is given by:
...