Help to build a function to approximate a expression when X >> Y
Subject: Help to build a function to approximate a expression when X >> Y
From: Stavros Macrakis
Date: Tue, 2 Oct 2007 13:02:50 -0400
>
> (a + b + c + d)*x + (d + e )*y +f
> try to write this in the form
> (a + b + c)*x + e*y + f + d *(x+y)
> and then subst x+y by x to get
> (a + b + c+ d)*x + e*y + f
I don't understand why this is a valid approximation. You could equally
rewrite the original expression as (a+b)*x + (e-c)*y + (d+c)*(x+y) + f =>
(a+b+c+d)*x + (e-c)*y + f.
-s