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Homework Help: Find d/dx of hyperbolic function

  1. Mar 9, 2008 #1
    [SOLVED] find d/dx of hyperbolic function

    1. The problem statement, all variables and given/known data
    Find:
    http://www.mcp-server.com/~lush/shillmud/1.1A.Q.JPG

    2. Relevant equations
    d/dx f(x)*g(x) = f(x) * d/dx g(x) + g(x) * d/dx f(x)
    d/dx f(g(x)) = d/dx f(g(x))* d/dx g(x)
    d/dx sinh x = cosh x
    d/dx cosh x = sinh x

    3. The attempt at a solution
    http://www.mcp-server.com/~lush/shillmud/1.1A.A.JPG

    Can this be further simplified? When I run it in maple I get:
    http://www.mcp-server.com/~lush/shillmud/1.1A.C.JPG

    I'm probably going to be posting here often so let me give you a little background. I am beginning calc II by correspondence. It is the last course of my undergrad and I haven't done any pure math courses in a while. I think things are going alright so far but without a prof or fellow students I sometimes become stuck or find it difficult to check an answer in a way that allows me to move on to the next question with confidence. I thought maple might help me check my answers but in this case it's left me more confused. Thanks for reading!

    P.S. How do I use special math characters (like infinite etc.) in my post as have seen some people do?
     
    Last edited: Mar 9, 2008
  2. jcsd
  3. Mar 9, 2008 #2

    HallsofIvy

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    What you have is perfectly correct. I can't speak for the Maple (especially not if they include "ln(e)" in the answer!
     
  4. Mar 9, 2008 #3

    Hurkyl

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    I expect it's simply a matter of applying a (hyperbolic) trig identity to show they are equal.

    Plugging in 5 or 6 (non-special!) values of x should, at least, give you high confidence that those expressions are, in fact, equal.
     
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