Questions
Question 1
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In a group table, what do the row label \(a\) and column label \(b\) represent?
Question 2
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What feature of a group table shows closure?
Question 3
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For a table with headings \(e,a\), the row \(e\) reads \(e,a\). What does this show about left multiplication by \(e\)?
Question 4
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If the entry in row \(a\), column \(b\) is \(e\), what inverse information does this provide?
Question 5
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Use the table row \(a\): entries under columns \(e,a\) are \(a,e\). What is \(a*a\)?
Question 6
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For \(G=\{e,a\}\) with \(a*a=e\), find \(a^{-1}\).
Question 7
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A table has headings \(e,a,b\). The row \(e\) is \(e,a,b\), but the column \(e\) is \(e,b,a\). Can \(e\) be a two-sided identity?
Question 8
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In a table for \(G=\{e,a,b\}\), row \(a\), column \(b\) is \(e\), and row \(b\), column \(a\) is \(e\). What can you conclude?
Question 9
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For addition modulo \(3\), compute the row for element \(1\) with columns \(0,1,2\).
Question 10
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For addition modulo \(4\), find the inverse of \(3\) by table reasoning.
Question 11
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Why must each row of a finite group table contain the identity exactly once?
Question 12
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A table has a row with a repeated entry. Explain why it cannot be a group table.
Question 13
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Build the Cayley table for \(\{0,1,2\}\) under addition modulo \(3\). Give the rows in order \(0,1,2\).
Question 14
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Given a finite group table, describe how to find all self-inverse elements.
Question 15
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A table is symmetric across its main diagonal. What does that suggest about commutativity, and what does it not prove?
Question 16
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A finite table has every row and column containing each element exactly once. Why is this still not a complete proof that the table defines a group?
Question 17
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Explain how row-first convention affects reading a non-commutative group table.
Question 18
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A student identifies an identity by finding only a row that reproduces the headings. Diagnose the mistake.
Question 19
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Prove that each column of a finite group table contains every group element exactly once.
Question 20
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A proposed table for four elements has one entry outside the listed set but otherwise looks like a group table. What is the decisive failure?