Iknow the answers to these questions, i just can't seem to figure out how to find the answers. i'm not too good at simplify the radical exprssion answer is simplify the radical expression (there's supposed to be a big suare root sign over the whole fraction) (^15 and ^11) answer is simplify the radical expression answer is

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