MathDB
fog=hog (similar functions)

Source: Romanian TST 1978, Day 1, P8

September 28, 2018
functionalgebradomain

Problem Statement

For any set A A we say that two functions f,g:AA f,g:A\longrightarrow A are similar, if there exists a bijection h:AA h:A\longrightarrow A such that fh=hg. f\circ h=h\circ g.
a) If A A has three elements, construct a finite, arbitrary number functions, having as domain and codomain A, A, that are two by two similar, and every other function with the same domain and codomain as the ones determined is similar to, at least, one of them. b) For A=R, A=\mathbb{R} , show that the functions sin \sin and sin -\sin are similar.