Recent content by shapiro478

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    Finding the Limit of F(s) as s Goes to Infinity: Exploring Exponential Order

    Say a function f and its derivative are everywhere continuous and of exponential order at infinity. F(s) is the Laplace transform of f(x). I need to find the limit of F as s goes to infinity. I use the integral definition of the Laplace transform and the fact that f is of exponential order...
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    How to Find Two Linearly Independent Solutions of (y' + f(x)y)' = 0?

    Say f is a continuous function on R. How could I find two linearly independent solutions of (y' + f(x)y)' = 0? Notice that there is no hypothesis about f being differentiable, so the obvious method of attack (taking the derivative of each term in the parenthesis and working off the resultant...
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    Proof of Compactness in X: C is Contained in F

    Office_Shredder -- I don't believe the epsilon-ball notion of open is valid here since we're working in some arbitrary topology "X", which is not necessarily the normal topology.
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    Proof of Compactness in X: C is Contained in F

    rs1n -- This new approach looks a lot more promising. I just have a question or two about this approach. M is a bunch (or even infinite number) of open subsets of X. When you intersect M with F, how do you know that the resultant intersection is still comprised of sets open in F? (is this an...
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    Proof of Compactness in X: C is Contained in F

    so it looks good JasonRox? thanks for your help
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    Proof of Compactness in X: C is Contained in F

    JasonRox -- The hypothesis does say C is compact in F... "If C is contained in F and compact in F..." Compact means every open cover has a finite subcover
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    Proof of Compactness in X: C is Contained in F

    Say X is a topological space and F is in X. If C is contained in F and compact in F, then C is compact in X. This is obvious when you draw a picture, but proving it is a little more difficult. By hypothesis, C is compact in F so C has a finite subcover M, with M being the union of m_1, m_2...
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