Let be X a topological space. Is an arc $f:[0,1]\to X $ with base point $x_0\in X$ a surjective function? I know that it is a continuous function. Can you help me?
2026-04-20 02:49:23.1776653363
Is an arc $f:[0,1]\to X $ with base point $x_0\in X$ a surjective function?
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No, not at all. You can just define the trivial loop by $f(x) = x_0$. If your space $X$ has more than $2$ elements this will not be surjective. In general you will pretty much never have surjective loops. To give an interesting looking example, look at the loop that I have drawn on this Möbius strip:
Clearly this does not cover the entire space.
P.S.: For some reason if I rescale the picture to medium size, the white background gets inverted. Sorry if the image is a bit huge now.