11.934321459

Discussion in 'Physics & Math' started by LionHearted, May 15, 2003.

  1. LionHearted Registered Senior Member

    Messages:
    105
    Is there anything significant about this number? I noticed that the function f(x) = -x(x+pi)(x-pi)/11.934321459 is the same as f(x) = sin x on the interval (-pi, pi). Is there any good reason for that number to be the denominator?
     
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  3. ryans Come to see me about a dog hey Registered Senior Member

    Messages:
    995
    Its not the same, it just looks the same. It looks like a taylor series expansion for sin(x) up to third order.
     
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  5. oxymoron Registered Senior Member

    Messages:
    454
    Special Numbers

    Okay, lets see who can work out what is so special about this number:

    142857

    Time's a tickin'
     
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  7. lethe Registered Senior Member

    Messages:
    2,009
    Re: Special Numbers

    repeating digits of 1/7
     
  8. James R Just this guy, you know? Staff Member

    Messages:
    37,189
    ...which also means it's a cyclic number.
     
  9. LionHearted Registered Senior Member

    Messages:
    105
    Re: Re: Special Numbers

    What do you mean by repeating digits of 1/7?
     
  10. everneo Re-searcher Registered Senior Member

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    2,621
    Re: Re: Re: Special Numbers

    1/7 = .142857142857142857...
     
    Last edited: May 15, 2003
  11. AntonK Technomage Registered Senior Member

    Messages:
    1,083
    EXCELLENT to finally see a thread not fighting about relativity! Wish i had more to add.

    -AntonK
     
  12. lethe Registered Senior Member

    Messages:
    2,009
    what s a cyclic number?
     
  13. oxymoron Registered Senior Member

    Messages:
    454
    Cyclic numbers are special numbers that when multiplied by an integer produces a number with the same digits but in a different order.

    142857 * 2 = 285714

    Sum of 142857 = 27

    Sum of 142857 * 8 = 27 as well.

    However 142857 * 7 = 999999, which means that a cyclic number multiplied by it's fraction-generator gives a string of 9's.

    I think these numbers are really cool. Apparently Lewis Carroll worked 142857 one out many, many years ago!

    Here is another cyclic number:

    588235294117647
     
  14. James R Just this guy, you know? Staff Member

    Messages:
    37,189
    142857 × 2 = 285714
    142857 × 3 = 428571
    142857 × 4 = 571428
    142857 × 5 = 714285
    142857 × 6 = 857142

    Multiples produce the same digits in a different order.

    <a href="http://mathworld.wolfram.com/CyclicNumber.html" target="_blank">Cyclic Numbers</a>
     
  15. Neat. Math without application is such a lonely thing is it not?

    It's like a play that's never acted out, A song that's never played, A dance that's never danced!
     
  16. ryans Come to see me about a dog hey Registered Senior Member

    Messages:
    995
    It's the best kind of math. All arguements are based on a few simple axioms which must be adhered to, other than that you can do anything you want. Personally I think theoretical physics is much more difficult to grasp than advanced mathemetics. Mathematics is bound by our logic, physics is bound by the logic of mother nature, who seems to be continually changing her mind.
     
  17. Canute Registered Senior Member

    Messages:
    1,923
    Didn't know about cyclic numbers. They have curious properties that look algorthymically useful. Have we found nature making use of them? (as with Fibonnachi series etc).
     
  18. ryans Come to see me about a dog hey Registered Senior Member

    Messages:
    995
    Don't know about cyclic numbers, but cyclic permutations have definately been used to describe nature.
     

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