Let a and b be rational numbers and a < b. Show that the class of closed intervals [a, b] is not a base for a topology on the real line.

What are the domain and range of the function? f(x) = -4 (sqrt)x

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

Anita has a success rate of 80% on free throws in basketball. she wants to know the estimated probability that she can make exactly four of five free throws in her next game. how can she simulate this scenario? categorize each simulation of this scenario as correct or incorrect.