Questions
Question 1
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What does it mean for an element \(g\) to generate a group \(G\)?
Question 2
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In multiplicative notation, what is \(g^0\)?
Question 3
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If \(r\) is rotation by \(90^\circ\), what rotation is \(r^2\)?
Question 4
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If \(g^5=e\) is the first positive return to the identity, what is the order of \(g\)?
Question 5
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List the distinct powers before repetition if \(g^4=e\) first occurs at exponent \(4\).
Question 6
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For rotations of an equilateral triangle generated by \(r\), where \(r\) is \(120^\circ\), list \(\langle r\rangle\).
Question 7
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In a cyclic group with \(g^6=e\), reduce \(g^8\) to one of \(e,g,g^2,g^3,g^4,g^5\).
Question 8
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In \(\mathbb Z_5\) under addition, what is generated by \(1\)?
Question 9
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In \(\mathbb Z_6\) under addition, list the elements generated by \(2\).
Question 10
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For a regular pentagon, let \(r\) be rotation by \(72^\circ\). What is the order of \(r\)?
Question 11
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Show that every element of a cyclic group commutes with every other element.
Question 12
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In a cyclic group generated by \(g\) with \(g^7=e\), find the inverse of \(g^3\).
Question 13
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Determine whether \(3\) generates \(\mathbb Z_8\) under addition.
Question 14
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Determine whether \(4\) generates \(\mathbb Z_{10}\) under addition.
Question 15
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If \(g\) has order \(12\), find the order of \(g^4\).
Question 16
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If \(g\) has order \(12\), find the order of \(g^5\).
Question 17
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Explain why stopping after seeing several distinct powers is not enough to prove an element generates a finite group.
Question 18
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Prove that if \(g\) has order \(n\), then \(g^{-1}=g^{n-1}\).
Question 19
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A student says a group of order \(6\) must be cyclic because repeatedly applying any non-identity element eventually repeats. Diagnose the error.
Question 20
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Show that every subgroup of a cyclic group is generated by powers of the same generator in the finite case, using the smallest positive exponent idea.