3 ms·
> I still wonder sometimes whether an infinite composition of continuous functions has to be continuous (limit of a sequence) ... No, as you expected. Take f(
by raegis 4y ago
> I still wonder sometimes whether an infinite composition of continuous functions has to be continuous (limit of a sequence) ...
No, as you expected. Take f(x) = x^2 on [0,1]. Then f(f(f(...f(x))) converges to g(x) = { 0, if 0 <= x < 1; 1, if x=1 }
- EGreg 4y agoRight. So now the question is -- are you able to give a physical example of physical (continuous) processes which can create a discontinuous output from a continuous initial state, in a finite amount of time? I think this is a sort of Zeno's paradox...
- juhanima 4y agoTossing a coin?
- EGreg 4y agoNo. The coin could land on its side, for instance, and stay there. Consider a pencil that is placed almost vertically, and then later drops to a horizontal position. There is a period where it is "unsure" where to go, and the more perfectly balanced it starts out, the longer this period is (assuming no wind etc.) That's what is being discussed.