Hetware wrote: > >So the answer is consensus among mathematicians holds that >F(t) = (t^2 - 9)/(t - 3) is undefined at t = 3?
>Perhaps what I should have said at the outset is something >along the lines of: on any given day, if I'm setting up an >equation in physics, and produce an expression such as >F(t) = (t^2 - 9)/(t - 3), I treat it as t + 3.
Then _define_ it as F(t) = t + 3.
If simplifying (t^2 - 9)/(t - 3) to t + 3 is correct in the context of your application, then simplify it in advance before defining the function.
>and do not expect any adverse consequence from doing so.
If the physical context makes removable discontinuities impossible, then _remove_ them. Don't leave them there in the definition of the function.