A concave mirror of focal length 'f' forms an erect image twice the size of an object. Find the object distance from the mirror.

Explanation

To solve the problem of finding the object distance from a concave mirror that forms an erect image twice the size of the object, we can follow these steps:

### Step 1: Understand the given information
We know that:
- The mirror is concave.
- The focal length of the mirror is denoted as 'f'.
- The image formed is erect and twice the size of the object.

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