# Search results

1. ### Aysmptotics : Need help with residues

ok I am starting to get it,,but what's happens if its a double pole.Do you work out the residues for both functions and multiply the 2 residues together or does it depend eg Gamma[s]Zeta[1-s] so the pole would be at 0. Since the Gamma fn and the Zeta are multiplied together you multiply the...
2. ### Aysmptotics : Need help with residues

Hey Is there a method in calculating the residues. Getting the poles is easy but i really don't know how my lecturer gets the residues eg. 1/2(Zeta[s]*Gamma[s/2] where at s = 1 it is Sqrt[Pi]/2 etc how does he do it?
3. ### Need help with a complex inequality?

for p = 1 |\frac{1}{2}(a+b)|\leq(\frac{1}{2}|(a+b)|)-ab isnt this false because you subtracting a ab on the RHS?
4. ### Need help with a complex inequality?

so you saying that |\frac{1}{2}(a+b)|^{p}\leq(\sqrt[p]{\frac{1}{2}}|(a+b)|)^{p}-pab \leq \frac{1}{2}(|a|^p+|b|^p)
5. ### Need help with a complex inequality?

Need help with a complex inequality?? hey! i been trying to do this inequality for a 2 hrs now and can't seem to prove it |\frac{1}{2}(a+b)|^p \leq \frac{1}{2}(|a|^p+|b|^p) where a,b are complex numbers Can anyone suggest a way?? thanks
6. ### Need help with a proof

ok,,thanks i also found the Fundamental Theorem of Algebra which I am reading up now. Thank you everyone! Cheers
7. ### Need help with a proof

I figured that we have to use complex numbers but we weren't told a method how to factorise complex polynomials with say n degree.Can you tell me a method of how to factorize a complex polynomial?? You mentioned that the quote above is the theorema egregium of Algebra which I am having...
8. ### Need help with a proof

the highest we ever gone up to is probably degree 5 that i know of..i'll try look up the theorem and see what you people are talking about
9. ### Need help with a proof

Do you know the name of it because of never heard of it.I wouldn't know where to start.If i have the name i can probably do some research on it and continue from there maybe
10. ### Need help with a proof

I don't see where you going.The roots you can get from the product..do want me to replace z with \cos\theta+i\sin\theta hmmm...with the LHS = (\cos\theta+i\sin\theta)^{n+1}-1=(\cos(n+1)\theta+i\sin(n+1)\theta)-1 and RHS =...
11. ### Need help with a proof

After learning a little latex maybe this looks better z^{n+1} - 1 =\Pi (z - e^\frac{2 \pi i(j+1)}{n+1}) where the product goes from 0<= j <= n
12. ### Need help with a proof

sorry!yes i was missing something in the original equation.So it suppose to look like this (z^(n+1))-1 = Product[(z-exp[2*Pi*i*(j+1)/(n+1)]) , 0<=j<=n] where Product[(z-exp[2*Pi*i*(j+1)/(n+1)]) , 0<=j<=n] = (z-exp[2*Pi*i*(0+1)/(n+1)]*(z-exp[2*Pi*i*(1+1)/(n+1)]*...*(z-exp[2*Pi*i*(n+1)/(n+1)]...
13. ### Need help with a proof

Hey!I have a tut question and I am having problems proving (z^(n+1))-1 = (z-exp[2*Pi*i*(j+1)/(n+1)]) where 0<=j<=n I tried doing it by induction which is easy for the 1st case with n = 1,I assume the case n-1 but then i get stuck with the last case. How will i know that all the z's with...
14. ### Help with combinatorics

ok,,so what i have now is correct?Just so i can get started...
15. ### Help with combinatorics

btw can you recommend a combinatorics book because he's notes help only a lil plus sometimes he doesn't explain himself properly(by the way we don't have a prescribed textbook) so anything we would be appreciated...
16. ### Help with combinatorics

Sorrie haven't replied for a while been kinda busy and sorrie again i thought there was a method because in our notes(which doesn't really help much) he has an example Suppose choose 25 objects from 7 types of objects s.t. every type of object appears at least twice and at most 6 times.. he...
17. ### Help with combinatorics

i need help with combinatorics...i need to finda ogf to compute the how many ways can 27 identical walls be distributed into 7 boxes, where the first box can contain at most 9 balls How do this??can you give me a method or explain to me how to do this step by step PLEASE! sAint
18. ### How do you do a combinatorial proof?

helps a bit so i wil just try some more of the exercises and see how it gows thanx..will ask if i need more help Saint
19. ### How do you do a combinatorial proof?

I still don't get how you do that... eg summation from k=0 to n (n k) {k is underneath n so basically its choosing k from n} = 2^n
20. ### How do you do a combinatorial proof?

How do you do a combinatorial proof? hey ppl! Im having a hard time trying to do a combinatorial proof! How do you start? WHat do you look at?? A general method would really help! Thanx SAint_n
21. ### Integrating sinx/x between (0,infinty)?

1) i don't know how to use MATLAB / mathematica (if u were thinking about it) 2) Gotta show all the working out hahaha
22. ### Integrating sinx/x between (0,infinty)?

i was thinking of approximating \int\frac{sinx}{x}dx\ by changing it into an alternating series where T(n) = \mid\int\frac{sinx}{x}dx\mid where n = 1... infinity and waz even thinking of using complex analysis to integrate it and we see when i get through it but I am also trying to...
23. ### Integrating sinx/x between (0,infinty)?

sorry! i forgot to mention it. But looks like everyone got the idea that it was (0,infinity) which it what i wanted. Found out that the method i mentioned before... i did a stupid thing by turning the minus to plus, DOPE!thanx
24. ### Integrating sinx/x between (0,infinty)?

writing T(n) = \mid\int\frac{sinx}{x}dx\mid Can u write sinx as a power series then dividing by x and integrating it then you get T(n) so T(n) = x + (x^3)/(3!3) + (x^5)/(5!5) + ... since i made my interval ( (n-1)\pi , n\pi) Why am i getting t(n) > t(n-1) What am i doing wrong??Can it...
25. ### Integral of sinx/x exists?

thanx for the help!My light bulb just went on!Couldnt av done it without ya Saint_n
26. ### Integrating sinx/x between (0,infinty)?

thanx for the help ppl!My light bulb just went on!Couldnt av done it without yas Saint_n
27. ### Integral of sinx/x exists?

integral of sinx/x exists? #1 saint_n Registered User Join Date: Apr 2004 Posts: 3 integrating sinx/x between (0,infinty)? -------------------------------------------------------------------------------- hey ppl! Can you help me by giving me a method or how you would go...
28. ### Integrating sinx/x between (0,infinty)?

integrating sinx/x between (0,infinty)? hey ppl! Can you help me by giving me a method or how you would go around to prove that this \mid\int\frac{sinx}{x}dx\mid exists. Thanx Saint_n
29. ### Limitsproving they exist?

How will you do \int\frac{sinx}{x}dx from zero to infinity. Which can be written as a alternating series T subscript n =\mid\int\frac{sinx}{x}dx\mid over intervals ((n-1)\pi,n\pi) but how do show as n tends to infinity that T(n) tends to 0? cos i can't integrate it
30. ### Limitsproving they exist?

limits..proving they exist? Wot do u have to do to prove that an intergral exists.?? I know how to do it if the integrals bounds are given ( example, [a,b]) but wot if the integral is from x till infinity??