# Ratio of product to difference - terminology?

## Main Question or Discussion Point

Is there a specific mathematical term, which refers to this expression?

A * B
------
A - B

tiny-tim
Homework Helper
hi dgm!
Is there a specific mathematical term, which refers to this expression?

A * B
------
A - B
not that i know of …

where did you come across this?

It can be expressed as the reciprocal of (1/B)-(1/A).

where did you come across this?
It's the form of an expression for the "room constant", a measurement in acoustics:

S*A
----
S-A

S is total surface area of a room, A is total absorption of a room in sabins.

It can be expressed as the reciprocal of (1/B)-(1/A).
Nice one. Thanks.