TITLE: Why are even/odd functions called even/odd?
QUESTION [10 upvotes]: Bit of a silly question, someone told me that the reason even functions are called 'even' and odd functions are called 'odd' is that all (single-variable) monomials with even powers are even functions and all monomials with odd powers are odd functions. In addition, this implies that the MacLaurin series (if it exists) of the odd part of a function is a linear combination of monomials with odd powers and similarly for the even case.  
I've done a google search about this, but I haven't had much success. Does anyone know if this the actual origin of the names 'even' and 'odd'?

REPLY [6 votes]: I know that the term "even" derives from the fact that the Taylor series of an even function contains only even powers, and so for the odd functions.