Question

Which function is NOT continuous?
a.
Your altitude as a function of time while flying from Reno to Dallas.
c.
Number of tennis balls that can fit completely inside a particular box as a function of the radius of the tennis balls.
b.
Time of travel from Miami to Pensacola as a function of driving speed.
d.
Area of a circle as a function of radius.

Answer 1

C is not continuous. 

Continuous functions have connected graphs; this indicates that every possible value of x has a value of y associated with it.  In this case, that says that every possible radius measurement has a number of tennis balls associated with it.  The problem with this is that we cannot have a fractional part of a tennis ball, so it is not continuous.

Answer 2

Number of tennis balls that can fit completely inside a particular box as a function of the radius of the tennis balls. C