When the muscles connected to the crystalline lens relax, the focal length is 9.0000 cm. With this focal length, how close must an object be to form sharply focused images on the retina? (Note: this distance is called the near point of vision.)

A candle (ho = 0.34 m) is placed to the left of a diverging lens (f = -0.051 m). The candle is do = 0.14 m to the left of the lens.  Numerically, what is the image distance, di in meters?

One method of measuring the focal length of a lens is to form an image of an object that is many focal lengths away from the lens. Show from equation (1/f=1/o+1/i)  that the image distance is approximately equal to the focal length when the object distance is very large (say, o=100f). What happens when the object distance become infinitely far away?

A 2 cm high object is viewed through a diverging lens with a -12 cm focal length. If the object is 8cm from the lens, then realtive to the lens where is the image and what is its height?