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=Problems that we have not yet done=
 
=Problems that we have not yet done=
  
==Practice Exam 4==
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==Practice Exam 4==  
 
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2. Let <math>(X,\mathcal{M}, \mu)</math> be a measure space with <math>\mu(X) =1</math> and let <math>F_1, \ldots, F_{17}</math> be seventeen measurable subsets of <math>X</math> with <math>\mu(F_j)=\frac{1}{4}</math> for every <math>j</math>.
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a. Prove that (some) five of these subsets must have an intersection of positive measure.
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b. Is the conclusion above true if we take sixteen sets instead of seventeen?
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5. Let <math>(X,\mathcal{M}, \mu)</math> be a measure space with <math>0<\mu(X) < \infty</math>. Assume that <math>f_n \to f</math> <math>\mu</math>-a.e. and <math>\|f_n\|_p \leq M < \infty</math> for some <math>1<p<\infty</math>. If <math>1\leq r <p</math>, show that <math>f_n \to f</math>/math> in <math>L^r</math>.
 
5. Let <math>(X,\mathcal{M}, \mu)</math> be a measure space with <math>0<\mu(X) < \infty</math>. Assume that <math>f_n \to f</math> <math>\mu</math>-a.e. and <math>\|f_n\|_p \leq M < \infty</math> for some <math>1<p<\infty</math>. If <math>1\leq r <p</math>, show that <math>f_n \to f</math>/math> in <math>L^r</math>.
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4. For <math>n=1,2,\ldots</math>, let <math>f_n:I\to \mathbb{R}, I =[a,b]</math> be a subsequence of functions satisfying the following: If <math>\{x_n\}</math> is a Cauchy sequence in <math>I</math>, then <math>\{f_n(x_n)\}</math> is also a Cauchy sequence. Show that <math>\{f_n\}</math> converges uniformly on <math>I</math>.
 
4. For <math>n=1,2,\ldots</math>, let <math>f_n:I\to \mathbb{R}, I =[a,b]</math> be a subsequence of functions satisfying the following: If <math>\{x_n\}</math> is a Cauchy sequence in <math>I</math>, then <math>\{f_n(x_n)\}</math> is also a Cauchy sequence. Show that <math>\{f_n\}</math> converges uniformly on <math>I</math>.
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==later==
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problem 3 on practice exams 7, 8, 9, and 10
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problem 5 on practice exam 11
  
 
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[[ 2010 Summer MA 598 Hackney|Back to 2010 Summer MA 598 Hackney]]

Revision as of 05:54, 26 July 2010


Problems that we have not yet done

Practice Exam 4

5. Let $ (X,\mathcal{M}, \mu) $ be a measure space with $ 0<\mu(X) < \infty $. Assume that $ f_n \to f $ $ \mu $-a.e. and $ \|f_n\|_p \leq M < \infty $ for some $ 1<p<\infty $. If $ 1\leq r <p $, show that $ f_n \to f $/math> in $ L^r $.


Practice Exam 6

4. For $ n=1,2,\ldots $, let $ f_n:I\to \mathbb{R}, I =[a,b] $ be a subsequence of functions satisfying the following: If $ \{x_n\} $ is a Cauchy sequence in $ I $, then $ \{f_n(x_n)\} $ is also a Cauchy sequence. Show that $ \{f_n\} $ converges uniformly on $ I $.

later

problem 3 on practice exams 7, 8, 9, and 10

problem 5 on practice exam 11

Back to 2010 Summer MA 598 Hackney

Alumni Liaison

Correspondence Chess Grandmaster and Purdue Alumni

Prof. Dan Fleetwood