How to get diff to yield result in terms of original function
Subject: How to get diff to yield result in terms of original function
From: Richard Fateman
Date: Fri, 09 Jan 2004 09:23:43 -0800
You may find "logarithmic differentiation" to be of interest,
if you want to maintain the original function names.
start with y=f(x)*g(x).....
take logs of both sides
log(y)=log(f(x)*g(x) ....)
take derivatives of both sides.
1/y* dy/dx = whatever
dy/dx= y*(.....) ;; note that y, or f(x)*g(x) ... is re-used.
RJF