Questions
Question 1
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State the squeeze theorem in words.
Question 2
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What are the three ingredients needed to use the squeeze theorem?
Question 3
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If \(-x^2\le f(x)\le x^2\) near \(0\), what is \(\lim_{x\to0}f(x)\)?
Question 4
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Why is \(-1\le\sin(1/x)\le1\) useful when evaluating limits near \(x=0\)?
Question 5
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Evaluate \(\lim_{x\to0}x^2\sin(1/x)\).
Question 6
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Evaluate \(\lim_{x\to0}x\sin(1/x)\).
Question 7
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If \(2-x^2\le f(x)\le2+x^2\), find \(\lim_{x\to0}f(x)\).
Question 8
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Evaluate \(\lim_{x\to0}x^4\cos(3/x)\).
Question 9
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Evaluate \(\lim_{x\to0}x^2\cos(1/x^2)\).
Question 10
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Evaluate \(\lim_{x\to0}x^2(3+\sin(1/x))\).
Question 11
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Explain why the inequality in the squeeze theorem only needs to hold near the approach point, not necessarily at the point itself.
Question 12
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Use \(|\sin u|\le1\) to show \(\lim_{x\to0}|x\sin(5/x)|=0\).
Question 13
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Evaluate \(\lim_{x\to0}x^2\left\lfloor\frac1{x^2}\right\rfloor\), where \(\lfloor y\rfloor\) is the greatest integer less than or equal to \(y\).
Question 14
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Evaluate \(\lim_{x\to0}x\left\lfloor\frac1x\right\rfloor\) as \(x\to0^+\).
Question 15
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Show that \(\lim_{x\to0}x^2\sin^2(1/x)=0\).
Question 16
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Evaluate \(\lim_{x\to0}\frac{x^2\sin(1/x)}{|x|}\).
Question 17
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A student tries to squeeze \(\sin(1/x)\) between \(-1\) and \(1\) and concludes \(\lim_{x\to0}\sin(1/x)=0\). Diagnose the error.
Question 18
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Use the squeeze theorem with \(\cos x\le\frac{\sin x}{x}\le1\) near \(0\) to find \(\lim_{x\to0}\frac{\sin x}{x}\).
Question 19
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Prove \(\lim_{x\to0}x\cos(1/x)=0\) using absolute values.
Question 20
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Suppose \(|f(x)-3|\le(x-2)^2\) for all \(x\) near \(2\). Prove \(\lim_{x\to2}f(x)=3\).