Exercise · ZW-CONTINUOUS-IMAGE-OF-CONNECTED-SPACE-010 · ★★★ Advanced

Let \(X=\{1,2,3\}\) with open sets \(\varnothing,\{1\},\{1,2\},X\). How many continuous maps are there from \(X\) to the discrete space \(\{a,b,c\}\)?

Choose one option.

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  • B. 3

Explanation

The image is connected, so every continuous map is constant, one for each element of \(\{a,b,c\}\): 3.

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Review the concept: Continuous image of a connected space

If \(f:X\to Y\) is a continuous function between topological spaces and \(X\) is connected, then the image \(f(X)\) is a connected subspace of \(Y\).

\[X\text{ connected},\ f\text{ continuous}\ \Longrightarrow\ f(X)\text{ connected}\]

More practice problems: continuous image of a connected space

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