Questions
Question 1
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Define conditional convergence for \(\sum a_n\).
Question 2
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State the two magnitude conditions used in the alternating series test.
Question 3
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Write the absolute-value series for the alternating harmonic series \(\sum (-1)^{n+1}/n\).
Question 4
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Do the magnitudes \(1/n\) tend to zero and decrease?
Question 5
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Show that \(\sum_{n=1}^{\infty}(-1)^{n+1}/n\) satisfies the alternating series test.
Question 6
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Show that the alternating harmonic series is not absolutely convergent.
Question 7
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Determine whether \(\sum_{n=1}^{\infty}(-1)^n/n^2\) is conditionally convergent.
Question 8
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Determine whether \(\sum_{n=2}^{\infty}(-1)^n/\ln n\) passes the alternating series test.
Question 9
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Show that \(\sum_{n=1}^{\infty}(-1)^{n+1}/\sqrt n\) converges conditionally.
Question 10
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Explain why conditional convergence depends on cancellation.
Question 11
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Why does the alternating series test not prove absolute convergence?
Question 12
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A series converges by the alternating series test, and its absolute-value series also converges. Is it conditional?
Question 13
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For which real \(p\) is \(\sum_{n=1}^{\infty}(-1)^{n+1}/n^p\) conditionally convergent?
Question 14
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Test \(\sum_{n=1}^{\infty}(-1)^n n/(n+1)\) for conditional convergence.
Question 15
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For which real \(p\) is \(\sum_{n=2}^{\infty}(-1)^n/(n(\ln n)^p)\) conditionally convergent, assuming the alternating test applies?
Question 16
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A signed approximation has terms \((-1)^{n+1}/n\). What warning does conditional convergence give about rearranging corrections?
Question 17
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Show that \(\sum_{n=1}^{\infty}(-1)^n\frac{\ln n}{n}\) is not absolutely convergent, and state the ordinary convergence idea.
Question 18
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Diagnose the error: the alternating harmonic series converges, so its absolute-value series must converge too.
Question 19
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Prove that conditional convergence requires two separate tests, not one.
Question 20
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A learner says every alternating series with terms tending to zero is conditionally convergent. Correct the statement with examples.