10 points. pls help me and explain

Write the expression as a constant , a single trigonometric function, or a power of a trigonometric function. sin x cos x/ tan x

An alternative to car buying is to make monthly payments for a period of time, and then return the vehicle to the dealer, or purchase it. this is called

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