Final answer:
Collecting 4 stereo speakers represents a discrete function because the number of speakers collected is countable and can only be whole numbers without fractions.
Step-by-step explanation:
If you are collecting 4 stereo speakers, this would represent a discrete function. Discrete functions consist of isolated points and are used when dealing with countable values, such as the number of books purchased or the number of stereo speakers collected. The number of speakers you have can only be whole numbers (1, 2, 3, 4), and it doesn't make sense to have a fraction of a speaker; hence, it is discrete. A continuous function, on the other hand, involves an unbroken, continuous set of values. Step functions jump from one value to another without taking on the values in between, which is not applicable to collecting speakers. A piecewise function is one that has different expressions for different intervals, which again isn't representative of simply collecting a set number of speakers.