What is the reciprocal of –5?
a.
–5
b.
- 1/5
c.
1/5 d 5 next question divide express your answer in lowest terms. 2/9 dived 1/4

Apinhole camera is made out of a light-tight box with a piece of film attached to one side and pinhole on the opposite side. the optimum diameter d(in millimeters) of the pinhole can be modeled by d=1.9[ (5.5 x 10^-4) l) ] ^1/2, where l is the length of the camera box (in millimeters). what is the optimum diameter for a pinhole camera if the camera box has a length of 10 centimeters