Recent content by gumi_kr

  1. G

    Need help for a statistical tool for my test

    So you have 2 sets of data: 1) calculations from your program 2) handmade calculations and you want to check it's accuracy, right? My thoughts: (i'm not advanced in statistics though): 1) define what's 'accurate' (5% error?) 2) If you want to then define 'Confidence interval' and do some...
  2. G

    Spectral Decomposition of Linear Operator T

    Try typing 'finding eigenvalues' in google and you will find your answer there. It is very common thing and you shall find it in any advanced 'linear algebra' book. (ctrl+f + eigenvalue) The general idea of 'spectral decomposition' is to find eigenvalues and vectors associated with it...
  3. G

    How can the sum of combinations be solved for the given problem?

    i was too excited to write it properly ;) 1) choose a group of (2M+2-k) people (from 2M+2) 2) choose a leader between them (multiply B(2m+2,2M+2-k) by 2M+2-k) 3) keep a leader and 'give' rest of the people to him (number of people 2M+2 - (2M+2-k) = k) 3) now you've got k people and a leader...
  4. G

    How can the sum of combinations be solved for the given problem?

    Sorry if i misunderstood what you've written but I think you are trying to prove wrong equality. Your proof is correct for {n\choose k} but we want to proove it for k{n\choose k}.btw1.Notice that because in our example n is even, we've got odd numbers of elements in this row of Pascal's...
  5. G

    How can the sum of combinations be solved for the given problem?

    Oh! Thats simple! \sum_{p=M+2}^{2M+2}\binom{2M+2}{p}p = \sum_{p=0}^{M+1}\binom{2M+2}{p}p We could create a simple bijection between this two sets. Let's simplify it: We know that: \binom{2M+2}{2M+2 -k}(2M+2-k) = \binom{2M+2}{k+1}(k+1) Why?: 1) choose...
  6. G

    How can the sum of combinations be solved for the given problem?

    about chaoseverlasting idea: We want to proove, that: \sum_{p=0}^{M}\binom{2M+2}{p}(M+1-p)=(2M+1)\binom{2M}{M} 1) Of course: (2M+1)\binom{2M}{m} = \frac{1}{2}(M+1)\binom{2M+2}{M+1} So let's change it and multiple both sides by 2...
  7. G

    How can the sum of combinations be solved for the given problem?

    "you can do this because the terms from 0 to m+1 are equal to the terms from m+2 to 2m+2, hence the sum on the right is twice the sum from 0 to m+1." could you explain it to me. I know it's true before differentiating, but why after? (* well it's not true before differentiating ;), my mistake...
  8. G

    How can the sum of combinations be solved for the given problem?

    Hi! Big thanks! i will check it later but it looks correct ("you can do this because the terms from 0 to m+1 are equal to the terms from m+2 to 2m+2!" I'm not sure about it yet) It really took me a lot of time trying to solve it. (as i thought changing this expresion /*with R_M^P)/ to...
  9. G

    How can the sum of combinations be solved for the given problem?

    Hi! Does anybody know how to solve the following problem: \sum_{p=0}^{M}\binom{2M+2}{p}(M+1-p)=? Well, actually i know that the solution is: (2M+1)\binom{2M}{m}=\frac{2^{2M+1}\Gamma(\frac{3}{2}+M)}{\sqrt{\pi}\Gamma(M+1)} but i cannot prove it (mathematica calculates the first...
  10. G

    Combinatorics/Probability problem.

    It was an usual exercise in probability theory course. It looks easy but I'm trying to solve this for a long time without success. 1) I know that trying simply to count it - isn't the right way (even using some advanced properties of binomial coefficient).2) It could be connected with Banach's...
  11. G

    Combinatorics/Probability problem.

    Homework Statement Let R ^{M} _{P}= \sum_{s=0}^{P} {M+1 \choose s}, for 0 \leqslant P \leqslant M , P,M\in \mathbb{N}. Proove that: \sum_{q=0}^{M}R^{M}_{q}\cdot R^{M}_{M-q}=(2M+1) {2M \choose M} and give it's combinatorical idea. I'm trying to solve this for 3 days - please help..
Back
Top