Explain the following three itemized questions about indrect proof
(a. k.a. reductio ad absurdum):
(1) how it works in terms of its unique procedure as a proof,
(2) why it constitutes a legitimate proof in spite of its unorthodox procedure
by identifying and explaining the two fundamental principles of logic as
its underpinnings; and
(3) why we accept those two principles.

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