undefined expressions

[kennap]

i've been searching through a calc textbook of mine to find what describes "undefined". I'm pretty sure it's got something to do with division by infinity (i cant remember or find were it is) can someone tell me, and discuss implications? Is they are type of math or problem sloving-technique involving 'undefined' terms?If i'm right about division by infinity i already see some startling implications. but then again maybe im way off... you tell me

[Robert]

Division by infinity gives 0. As the denominator gets larger the fraction gets smaller and approaches 0. Undefined is when you you divide by 0. Computers especially don't like this. Sometimes an equation might have some undefined terms or infinity terms, but if you're lucky they will cancel out leaving you with a viable equation. Sometimes a problem appears to be unsolvable until you take a different approach, involving the complex plane, for example, and these undefined and infinity parts of the equation become manageable. However, I'm not a mathematician. Maybe someone else can provide more insight.

I'd love to hear about the implications you see with these undefined and infinities. They are quite interesting. --Robert