Recent content by mimsy57

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    Assessing Chance of Donation with Bayes Law

    Thanks! I was totally missing the sequential nature.
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    Assessing Chance of Donation with Bayes Law

    Homework Statement Each year, a man will donate money to a charity with chance x [0,1] (chosen the first time he donated, and not changing), with the prior distribution P(x)=x^3+2x-1/4. Use Bayes law to find a posterior distribution given these observations and help the charity determine if...
  3. M

    Taylor expansions in two variables

    1. Problem: if f(1,3)=7, use Taylor expansion to describe f(1.2,3.1) and f(.9,2.8) if the partials of f are give by df/dx=.2 d^2f/dx^2=.6 df/dy=.4 d^2f/dy^2=.9 (you do not need to go beyond the second derivative for this problem) 2. I know from class how to do this if one variable changes...
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    Looking for method to use in final step in heat equation problem

    Thanks! This looks more like what I would know how to do. I appreciate your help!
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    Looking for method to use in final step in heat equation problem

    Okay, thanks, I really appreciate your help. This is seeming a little advanced...we haven't gone over anything like this. Could I have made a mistake earlier on? From the fact that you found the negative error, it sounds like you did it and got the same thing. Is there some way for me to...
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    Looking for method to use in final step in heat equation problem

    Thanks! I've been looking at this, and I think I must be using it incorrectly because I am ending up in the same place. If I rearrange the negative to be in the same form as the page you referenced and look at the homogeneous equation: y''+(1/2)xy'-3/2y=0 then using the labels from...
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    Looking for method to use in final step in heat equation problem

    Homework Statement The original problem is to solve u_t=u_xx+x with u(x,0)=0 and u(0,t)=0 by assuming there is a solution t^a*u(r), where r=x/t^b and a,b are constants Homework Equations The Attempt at a Solution This is a long problem, so I'm not writing everything. Following the...
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    Uncovering the Error in Finding the Mobius Transformation for a Circle Mapping

    Yes about the three points. My problem isn't so much with that, I'm okay calculating it, I'm just bothered by how it can work. If I translate a circle, rotate a circle, or dilate a circle, or invert a circle, I don't see how points on a quarter arc could move to a half arc. Does my...
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    Uncovering the Error in Finding the Mobius Transformation for a Circle Mapping

    I'm looking for the error in my understanding here, not help with the problem itself. I'm making some kind of mistake, so I've listed out everything I think I know, and I'm hoping someone can either tell me what I'm misunderstanding, or tell me there is an error in the problem statement...
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    Show That f(x,y) Must Be a Constant: A Complex Harmonic Function

    ha, that's embarrassing (I really did know that as you can see from my first post). I've been looking at this one too long. Thanks! So it must be that it is supposed to be a real function, not complex. I'll have to check with the professor on that. So then it should be simpler. Now I'm...
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    Show That f(x,y) Must Be a Constant: A Complex Harmonic Function

    oh okay, just figured part of my confusion out. If the whole function is analytic then each part is harmonic and they have to be harmonic conjugates. Still confused on the other portions.
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    Show That f(x,y) Must Be a Constant: A Complex Harmonic Function

    Maybe I am having some deeper conceptual problem. I am now confused on several points (I think Morphism may have hit on it in that I am most likely misunderstanding what it means to be a complex harmonic function): 1. How is the function f(x,y)=x+iy harmonic? u would be x and v would be y...
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    Show That f(x,y) Must Be a Constant: A Complex Harmonic Function

    If what you are saying in your last post is correct, then the problem itself wouldn't make sense. But what are you using to determine that f^2 is harmonic? The product of harmonic functions need not be harmonic. Also, just to clarify with my confusing title: Assumptions: f and f^2 are...
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    Show That f(x,y) Must Be a Constant: A Complex Harmonic Function

    No, sorry, my error. That should have said "if the square is also harmonic."
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