What is the equation in point−slope form of the line passing through (2, 2) and (4, 8)?

a. (y − 2) = 3(x − 2)
b. (y + 2) = 3(x + 2)
c. (y − 8) = −3(x − 4)
d. (y + 8) = −3(x + 4)

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