Mathematical terms in popular usage

[Mark A. Mandel]

On Wed, 21 Apr 2004 JJJRLandau at aol.com wrote:

#tangent, as in "off on a tangent".  This is really reaching, but the math
#meaning of "tangent" is the direction the curve were going at a specified time or
#point, and could remain quite close to where the curve is currently going,
#whereas the popular usage implies "going in a quite different direction".

I've seen a .sig line something like the following:

If you don't go off on a tangent, you'll keep going around in circles.

-- Mark A. Mandel