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Math Help

  1. Jun 6, 2005 #1
  2. jcsd
  3. Jun 6, 2005 #2
    Please try not to double post, it can be confusing for those helping you.
  4. Jun 6, 2005 #3
    sorry... i posted in physics and didnt realize it... and i didnt know how to move it
  5. Jun 7, 2005 #4


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    if you know hebrew, he IS THE GURU... (many good ppl in the hebrew univ' learned from it)
    David Maizler, "Heshbon Infinitesimali"
    Morris Kline's "Calculus, An Intuitive & Physical Approach". ISBN: 0-486-40453-6
    rigorous text, not an intuitive one:
  6. Jun 7, 2005 #5
    eh? what are you talking about, this is a basic calculus problem to demonstrate the definition of the derivative.

    eutopia, notice that you can write:

    [tex]| 3x - 6 | < \epsilon[/tex]
    [tex]| x - 2 | < \delta[/tex]

    What if we multiplied the second inequality by 3?

    and be sure to check your book again...i would be surprised if your calculus text did not have a section on the modern definition of the derivative.
  7. Jun 7, 2005 #6
    Shalom, ma shlomha?

    Let's cheat a little.

    You know the slope of the line is 3, right? Since f(x) = 3x + 1, then m = 3.

    It is not hard to imagine that "e" and "d" are rise and run. So we could write this: 3 = e/d.

    The question is, for every rise, is there a run (for every e, is there a d)? The answer is yes. We know that 3 = e/d, we can solve for d:

    d = e / 3.

    This is just another way to help you think of the problem. e and d is the slope finding game. I give you an e, you give me a d.

    Does the line 3x + 1 have a slope everywhere? Of course.

    Now, this method covers the trivial case, but it gives you another way to look at it. Imagine a function besides a line that does not have one single slope, like m = 3, then you start getting into slope functions.

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