

A Schwartz function is a "rapidly decaying" function, in the sense that the function and all its derivatives decay faster thanfor n = 1,2,3,4,...
Schwartz space - Wikipedia, the free encyclopedia
Those functions are certainly even, but none of them is Schwartz... the first two only decay as fast as, and the last decays much slower than that (as
). So, the Schwartz thing isn't useful here.