9,73,241,561,1081,1849,_?_
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9,73,241,561,1081,1849,_?_
1–10 of 91 posts
Re: 9,73,241,561,1081,1849,_?_
#2Re: 9,73,241,561,1081,1849,_?_
#3I read the title here which has no spaces between the numbers (a real pet peeve :P) then went on to read the explanation of "Edwin's" attempts to solve the blank. Except without the spaces, I thought he was trying to find the remaining digits of a single number (with commas for thousands separator).
(before clicking the link, I was expecting "find the remaining digits to make this number a prime" or something)
Nice link though!
Re: 9,73,241,561,1081,1849,_?_
#4I hit my head to wall after reading this. Difference table is a really cool way to solve this kind of questions. I thought "how come I have never learned this difference table before". I could make better points with IQ tests with difference tables :)
Re: 9,73,241,561,1081,1849,_?_
#5I discovered difference tables as a kid, didn't know they were used much, I was modelling motion on a 2D display (an oscilloscope hooked to a P2P11!). Was a lifesaver for quick polynomial evolution - uses only addition, execution time scales linearly with the order of the polynomial.
So, how do you go from the difference table "coefficients" to the polynomial?
Re: 9,73,241,561,1081,1849,_?_
#6I discovered difference tables as a kid, didn't know they were used much, I was modelling motion on a 2D display (an oscilloscope hooked to a P2P11!). Was a lifesaver for quick polynomial evolution - uses only addition, execution time scales linearly with the order of the polynomial. So, how do you go from the difference table "coefficients" to the polynomial?
It's a bit non-trivial, but mechanically solvable. Polynomial coefficients are for normal powers. Difference table coefficients have more to do with falling powers (x * (x-1) * (x-2) * ...). Look up "Finite Calculus" or "Difference Equations" if you are interested.
Re: 9,73,241,561,1081,1849,_?_
#7[deleted]
Re: 9,73,241,561,1081,1849,_?_
#8why is this at the top?
Re: 9,73,241,561,1081,1849,_?_
#9why is this at the top?
because it is interesting.
Re: 9,73,241,561,1081,1849,_?_
#10I discovered difference tables as a kid, didn't know they were used much, I was modelling motion on a 2D display (an oscilloscope hooked to a P2P11!). Was a lifesaver for quick polynomial evolution - uses only addition, execution time scales linearly with the order of the polynomial. So, how do you go from the difference table "coefficients" to the polynomial?
I'm not sure if this is your question, but divided differences are a way to do polynomial interpolation, with efficient updating to account for new data points: http://en.wikipedia.org/wiki/Newton_polynomial