# Math Help - Derivative Question --> Rate of Change with focal length formula

1. ## Derivative Question --> Rate of Change with focal length formula

Question:

If is the focal length of a convex lens and an object is placed at a distance from the lens, then its image will be at a distance from the lens, where , , and are related by the lens equation
What is the rate of change of with respect to if and ?

(My work is attached)

Any help would be greatly appreciated!

2. Originally Posted by s3a
Question:

If is the focal length of a convex lens and an object is placed at a distance from the lens, then its image will be at a distance from the lens, where , , and are related by the lens equation
What is the rate of change of with respect to if and ?

(My work is attached)

Any help would be greatly appreciated!