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Thread: (n^(4/5))! = 20922789888000

  1. #1 (n^(4/5))! = 20922789888000 
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    Is there any way to solve

    Besides trial and error? I can't figure it out!

    Thanks in advance!

    I have taken the liberty of "texing" your question. If I have it wrong, that is your fault USE THE TEX FACILITY IN FUTURE


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  3. #2 Re: (n^(4/5))! = 20922789888000 
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    Quote Originally Posted by m84uily
    Is there any way to solve

    Besides trial and error? I can't figure it out!

    Thanks in advance!

    I have taken the liberty of "texing" your question. If I have it wrong, that is your fault USE THE TEX FACILITY IN FUTURE







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  4. #3 Re: (n^(4/5))! = 20922789888000 
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    Quote Originally Posted by DrRocket




    Thanks! But how do you compute


    ?
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  5. #4 Re: (n^(4/5))! = 20922789888000 
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    Quote Originally Posted by m84uily
    Quote Originally Posted by DrRocket




    Thanks! But how do you compute


    ?
    Basically the same way you compute that 27/9=3. There you invert multiplication. Here you invert !

    Didn't you learn your factorial tables when you learned the multiplication tables as a kid ?
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  6. #5 Re: (n^(4/5))! = 20922789888000 
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    Quote Originally Posted by DrRocket
    Basically the same way you compute that 27/9=3. There you invert multiplication. Here you invert !

    Didn't you learn your factorial tables when you learned the multiplication tables as a kid ?
    No, I hadn't.
    So this would have to be something that comes from memory rather than something like:



    ?
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  7. #6 Re: (n^(4/5))! = 20922789888000 
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    Quote Originally Posted by m84uily
    Quote Originally Posted by DrRocket
    Basically the same way you compute that 27/9=3. There you invert multiplication. Here you invert !

    Didn't you learn your factorial tables when you learned the multiplication tables as a kid ?
    No, I hadn't.
    So this would have to be something that comes from memory rather than something like:



    ?
    More like

    leads to

    So

    leads to

    Doesn't everybody do this in their head ? At least for ?
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  8. #7  
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    I went to school during the Reagan era, so consequently I wasn't even exposed to the concept of factorials(!), much less exposed to a table of such. I only learned of factorials about two years ago.
    It should be fairly easy to construct a factorial table. From there I might be able to spot a pattern that might lead to an algorithm for extrapolating the factorial base of a number. Or, I could just use Google, "formula for extrapolating factorial base", but that wouldn't be much fun.
    I was some of the mud that got to sit up and look around.
    Lucky me. Lucky mud.
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  9. #8 Re: (n^(4/5))! = 20922789888000 
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    Quote Originally Posted by DrRocket

    Doesn't everybody do this in their head ? At least for ?
    Yeah, I just wanted to know how to do it for larger numbers, maybe I should have started by inquiring about that. Sorry!
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  10. #9 Re: (n^(4/5))! = 20922789888000 
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    Quote Originally Posted by DrRocket
    Doesn't everybody do this in their head ? At least for ?
    I sure don't.
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  11. #10  
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    Quote Originally Posted by GiantEvil
    I went to school during the Reagan era, so consequently I wasn't even exposed to the concept of factorials(!), much less exposed to a table of such. I only learned of factorials about two years ago.
    It should be fairly easy to construct a factorial table. From there I might be able to spot a pattern that might lead to an algorithm for extrapolating the factorial base of a number. Or, I could just use Google, "formula for extrapolating factorial base", but that wouldn't be much fun.
    One thing you can do to solve for n! = Blah, is to divide "Blah" by 1, 2, 3, etc, until you get 1.

    So, it's easy to solve for n! = Blah, but I wouldn't be able to do it just by glancing at it.
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  12. #11  
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    Quote Originally Posted by salsaonline
    Quote Originally Posted by GiantEvil
    I went to school during the Reagan era, so consequently I wasn't even exposed to the concept of factorials(!), much less exposed to a table of such. I only learned of factorials about two years ago.
    It should be fairly easy to construct a factorial table. From there I might be able to spot a pattern that might lead to an algorithm for extrapolating the factorial base of a number. Or, I could just use Google, "formula for extrapolating factorial base", but that wouldn't be much fun.
    One thing you can do to solve for n! = Blah, is to divide "Blah" by 1, 2, 3, etc, until you get 1.

    So, it's easy to solve for n! = Blah, but I wouldn't be able to do it just by glancing at it.
    It is considerably easier if you have a calculator with a factorial function built in. :-D
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  13. #12  
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    Quote Originally Posted by salsaonline
    One thing you can do to solve for n! = Blah, is to divide "Blah" by 1, 2, 3, etc, until you get 1.
    I can't believe I didn't figure that out for myself.
    I went so far as to construct a factorial table to 16! Then I factored the 16! down to 2^15,3^6,5^3,7^2,11 and 13.
    I randomly picked 9! and got 2^7,3^4,5 and 7.
    I didn't see any pattern yet so I quit for the moment.
    I was some of the mud that got to sit up and look around.
    Lucky me. Lucky mud.
    -Kurt Vonnegut Jr.-
    Cat's Cradle.
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