A​ 35-mm camera allows you to control the diameter d of the aperture by changing the​ f-stop, which varies inversely with the diameter according to the formula f
.
a. If f​, find the diameter.
b. If the is ​, by what factor will the ​change?
c. The radius r is​ one-half of the diameter. Describe the proportional relationship between the radius and the diameter.
d. Area A is proportional to the radius squared according to the equation Ar. What is the equation that relates area and​ diameter?
e. What is the equation that relates area and​ f-stop?
