3. The amount of light captured by a lens,L(f),is a function ofthe lens’s focal length,f.L(f) ismeasured in lumens (lm) andfismeasured in millimeters (mm).(a) The amount of light captured by alens with a focal length of 5 mm is 1000 lm. Expressthisinformation in terms ofL.(b) Interpret the meaning ofL(10) =4000.