[math-fun] oddity

Shew that odd 2 i k pi 2 i k pi ==== -------- -------- \ odd odd > e oddfun(e ) / ==== k = 1 odd i (2 k - 1) pi i (2 k - 1) pi ==== -------------- -------------- \ odd odd = > e oddfun(e ) / ==== k = 1 Easy but not trivial. --rwg