Re: [math-fun] term for f(a b) = a f(b) + b f(a)?

"N. J. A. Sloane" <njas@research.att.com> wrote:

Marc asked:

...

Is there term for when f(a b) = a f(b) + b f(a)?

This is called a "derivation" and is better written

f(a b) = a f(b) + f(a) b

See e.g. Bourbaki, Lie Groups, Vol 1 , Chap 1, section 1, para 1, page 2 !

A derivation must also be linear (by definition). --Bill Dubuque