Recent content by Shaji D R

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    A Essentially bounded functions and simple functions

    I need help. I forgot to indicate that the function is measurable also.
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    A Essentially bounded functions and simple functions

    How to prove that essentially bounded functions are uniform limit of simple functions. Here measure is sigma finite and positive.
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    Lebesgue measure in lower dimensional space

    You are correct. Thank you very much!
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    Lebesgue measure in lower dimensional space

    We can assume some familiarity of Matrix and Determinants. Definitely in xy plane rotation is a Linear Mapping.z-axis will be the axis of rotaion. x' = xcosø-ysinø and y'=ycosø-xsinø and z' = z - This can be expressed as a matrix(of Linear Transformation).(Rotaion by an angle ø in xy plane...
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    Lebesgue measure in lower dimensional space

    See the phrase "is countable as countable union of finite sets". In the step above that, epsilon in the right side should be replaced by 1/n, I think. Union on the right side should be over n. (I am not sure). Thank you very much for the proof. But how I was supposed to prove this while...
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    Lebesgue measure in lower dimensional space

    Your proof is tough! Looks like there are some small mistakes in the proof. For example "for all i" should be replaced by "for all j". one "> epsilon" should be replaced by "> 1/n". One major doubt is that in the proof it is assumed that measure of A is finite. Consider my example V =...
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    Lebesgue measure in lower dimensional space

    "Real And Complex Analysis" by Walter Rudin 3rd Edition, Theorem 2.20 Page No:50, 51,52 The sentence troubling me is "If range of T is a subspace Y of lower dimension, Then m(Y) = 0..."
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    Lebesgue measure in lower dimensional space

    The context is that I am reading the proof that Lebesgue measure is rotation invariant Let X be a k-dimensional euclidean space. T is a linear map and its range is a subspace Y of lower dimension. I want to prove that m(Y) = 0 where m is the lebesgue measure in X. How to prove this...
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    Dedekind Cut and Archemedean Q

    OK. Looks like I got the answer. It was a trivial case. If there is no such n then nw is a member of alpha for every n by induction. Since aplpha is not equal to Q and Q is archemedian it is not possible.If q is not a member of alpha then q > any member of alpha and nw > q for some n.And nw...
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    Dedekind Cut and Archemedean Q

    Let α be a Dedekind Cut. w a positive rational.How to prove that there exists a integer n such that nw is a member of α and (n+1)w is not a member of α, using Archemedian propoerty of Q. Suppose p is a member of α. we can find n such that nw < p < (n+1)w. So nw is a member of α. Further I am...
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    Can open sets and closures intersect in a topological space?

    Suppose A and B are open sets in a topological Hausdorff space X.Suppose A intersection B is an empty set. Can we prove that A intersection with closure of B is also empty? Is "Hausdorff" condition necessary for that? Please help.
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    Principles Of Mathematical Analysis-Walter Rudin

    I am asking the question honestly. Equ.43 is proved for any rational number and taken as definition for any real number and author claims that the definition is equivalent to equ.33 chapter 8(which is another definition). Author claims continuity and monotonicity of L is required for the proof...
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    Principles Of Mathematical Analysis-Walter Rudin

    No. We are not using continuity of any function here. If there is no rational p < x with g(x) < f(p) < f(x), then f(x) is not the supremum. supremum will be < or = g(x).Note that f(x) is defined as f(x) = sup( k raised to y) (y rational , y<x)(k>1). Also continuity of L(k) is the issue. In the...
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    Principles Of Mathematical Analysis-Walter Rudin

    E&L E is defined by equation 25 chapter 8 page no 178 i.e., E(z) = Sigma(n=0 to INF)( (z raised to n)/(n!)) and L is inverse of that.Why the inverse exists, why E(z) is continuous and monotonically increasing like that are proved in the book. Finally the author defines x raised to y as...
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