On the continuity and monotonicity of restrictions of connected functions
Professor Z. Krygowska in her article, opening the frst issue of the PTM (Polish Mathematical Society) journal Didactics of mathematics (Dydaktyka Matematyki), (Krygowska, 1981) noted that the teacher and his preparation, and thus the problems of teaching mathematics, are never ahistorical. We live here and now, our pupils (students, doctoral students) are immersed in the contemporary time and in the current form of being. The Internet, computer games, the considerable computational capabilities...
We prove some results concerning the entropy of Darboux (and almost continuous) functions. We first generalize some theorems valid for continuous functions, and then we study properties which are specific to Darboux functions. Finally, we give theorems on approximating almost continuous functions by functions with infinite entropy.
In the paper the existing results concerning a special kind of trajectories and the theory of first return continuous functions connected with them are used to examine some algebraic properties of classes of functions. To that end we define a new class of functions (denoted ) contained between the families (widely described in literature) of Darboux Baire 1 functions () and connectivity functions (). The solutions to our problems are based, among other, on the suitable construction of the ring,...
Page 1