Editing Even and odd functions (section)

==Early history==

The concept of even and odd functions appears to date back to the early 18th century, with [[Leonard Euler]] playing a significant role in their formalization.  Euler introduced the concepts of even and odd functions (using Latin terms ''pares'' and ''impares'') in his work ''Traiectoriarum Reciprocarum Solutio'' from 1727.  Before Euler, however, [[Isaac Newton]] had already developed geometric means of deriving coefficients of power series when writing the ''Principia'' (1687), and included algebraic techniques in an early draft of his ''Quadrature of Curves,'' though he removed it before publication in 1706.  It is also noteworthy that Newton didn't explicitly name or focus on the even-odd decomposition, his work with power series would have involved understanding properties related to even and odd powers.