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Topology · Lesson 08
Eight questions across both properties, with no teaching blocks. Deciding which of the two a question is about, and which direction the argument runs, is the work here.
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Sign in to save progressEight questions across both properties, with no teaching blocks. Deciding which of the two a question is about, and which direction the argument runs, is the work here.
Two tools on the bench and no label on the job. Picking up the right one is most of the skill.
Both properties are stated in open sets alone, and both survive a continuous map. Neither implies the other.
: compactness.
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Which space is compact?
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To show a space is not compact, what is enough?
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A continuous map sends a compact space onto . What follows?
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Which two facts does this chapter use without proving them?
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is compact and is closed. What follows?
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In a metric space, which implication is true?
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Exactly one of these subsets of is compact. Which?
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A metric space is sequentially compact. What follows?
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A continuous real function on a compact space attains a largest value.
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The cover of by the intervals for is given. How many members does the smallest subcover have?