Fundamental theorem of algebra implies that every real polynomial of degree �has at most nreal zeros. Descartes� rule of signs determines the maximum number of positive and negative real roots of a polynomial. We propose function families possessing these properties on the number of real zeros. These function families include polynomial functions and sums of exponential functions.

Descartes� rule of signs, fundamental theorem of algebra, number of zeros, real function family, polynomial, sum of exponential functions.