**Examples
for subject**

Example #1

Problem:

a.) An image is
located at exactly the same position as an object for a mirror of
focal length 6 *cm*. What is the object distance?

Solution:

Use the formula with **d**_{i}
and equal to get

**d**_{o
}= 12 *cm*

b.) If the height
of the object is 4.5 *mm*, what is the height of the
image?

Solution:

Use to see that the image height equals the object height.

**h**_{i
}= - 4.5 *mm* (inverted)

Example #2

Problem:

a.) A
convex mirror has an object 14 *cm *from the mirror, and
the image appears to be 7 *cm* behind the mirror. What is
the focal length of the mirror?

Solution:

Use the formula with the image distance negative.

* f* =
-14

b.)
If the object height is 8.0 *mm*, what is the height of
the image?

Solution:

Use the formula with the image distance negative.

**h**_{i} =
4.0 *cm* (upright)