please do part A and part B for problem 1 and also please do problem 2 if i don't get A or B on this i fail this class so please help 30 pts and brainiest

What is the relative minimum of the function? enter your answer in the box.

How to determine whether two known pairs of points are on the same line.

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