Let be an odd function and let be an even function.
What can be said about ?
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
o ( o ( e ( o ( e ( o ( − x ) ) ) ) ) ) = o ( o ( e ( o ( e ( − o ( x ) ) ) ) ) ) = o ( o ( e ( o ( e ( o ( x ) ) ) ) ) ) therefore the function is even.
It can be done intuitively by considering a negative sign going down through filters (odd functions let it go further but even expel it) so if the composed funtion has at least one even function the hole is even.