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Messages 7547 - 7576 of 13927   Oldest  |  < Older  |  Newer >  |  Newest
Messages: Simplify | Expand   (Group by Topic) Author Sort by Date ^
7547
n(1+x)^(n-1) n is a constant. If f(x) = n(1+x)^(n-1) = [n].(1+x)^(n-1) then f'(x) = [n].(n-1)(1+x)^(n-2) (thanks to the chain rule) = (nČ-n).(1+x)^(n-2)....
clooneman
Offline
Apr 1, 2004
1:05 pm
7548
You've differentiated the wrong function. Start with equation (2) n x(1+x)^(n-1) = Sum{C(n,k) k x^k} The LHS of this equation is n x(1+x)^(n-1) Differentiate,...
jwwarrenva
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Apr 2, 2004
12:52 am
7549
... I get it now. So the questions I'm posing are; 1)What is the notation for this method if this continues for higher degrees of the polynomials in k and n...
bqllpd
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Apr 2, 2004
1:50 am
7550
... Sorry... it should be Sum{((-3)^(n-k))*C(n,k)*(2k^2+k+3), k=0 to n}...
bqllpd
Offline
Apr 2, 2004
1:54 am
7551
Times 4^k god i really should proof read before i post...
bqllpd
Offline
Apr 2, 2004
1:56 am
7552
I Guess that everyone knows what are Closed Sets and Compact Sets . Give me a set which is finite , closed and not Compact . __________________________________...
Vijay
v0121223
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Apr 2, 2004
7:25 am
7553
I think it is not possible, a finite set is always compact (it doesnŽt matter if it is closed or not). A set is compact if for every open covering of it you...
lucasbl3
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Apr 2, 2004
12:49 pm
7554
Any set with finitely many elements is closed(since there are no limit points that are not in the set.) Likewise it is compact. This is true in every metric...
arcanuum
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Apr 3, 2004
6:27 am
7555
Easier proof----any topology on a set X is a subset of the power set P(X)= the set of all subsets of X. So if X has cardinality n < 00 then any open covering...
Adam
a_math_guy
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Apr 3, 2004
3:06 pm
7556
But the original post didn't say metric space......thinking whether it is true in non-separable spaces. Probably not, hunh. Say X is a set with topology :...
Adam
a_math_guy
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Apr 3, 2004
3:15 pm
7557
Whoops! When I incorrectly typed ... I should have typed "every sequence in the set has a subsequence which converges to a point in the set." And the sequence...
arcanuum
Offline
Apr 3, 2004
5:12 pm
7558
... This ... What's really important is that the compactness of a set S is a property depending on the topology of S and NOT on the topology the space S is...
Julien
julien_santini
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Apr 3, 2004
5:32 pm
7559
... whether ... a ... You mean: every set which contains p0 is an open set and the empty set is open. OK ... closure ... this ... What did you try to prove ?...
Julien
julien_santini
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Apr 3, 2004
5:47 pm
7560
this is getting embarrassing. I have to correct my "correction to #7544. The post I am referring to is actually #7554, not 7544. lol I do fine with...
arcanuum
Offline
Apr 3, 2004
8:54 pm
7561
... Hehe... It's so funny but it's true. Once I was playing a game of 500 with my friends (a card game), and I was keeping score. The score goes up only by...
derpified
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Apr 4, 2004
3:52 am
7562
I'm trying to differantiate y=x^(1/x) I got: dy/dx=(1/x)*x^(1/x-1)*(-1/x^2) using the power rule, chain rule and quotient rule, but that's apparently...
michaelsgdec
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Apr 4, 2004
9:22 pm
7563
Logarithmic differentiation. y=x^(1/x) so log y = (1/x)logx by log rules of powers differentiate (1/y)(dy/dx)=(-x^-2)(log x) + (1/x)(1/x) by product rule =...
Jen
mussed_up
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Apr 4, 2004
10:25 pm
7564
Consider this: y=x^(1/x) ==> y^x = x And differentiate that. xy^(x-1).dy/dx = 1 or whatever dy/dx = 1/[xy^(x-1)] = 1/[x^(1+1/x)] I hope that's right, but it's...
clooneman
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Apr 5, 2004
1:03 pm
7565
The power rule, like any other mathematical theorem, has hypotheses associated with it. It says that IF n is a CONSTANT then d/dx ( x^n ) = n x^(n-1) If you...
arcanuum
Offline
Apr 5, 2004
2:29 pm
7566
Wasn't the "= y(1/y)(dy/dx)" part a bit redundant? ... _____________________________________________________________________...
clooneman
Offline
Apr 5, 2004
4:56 pm
7567
The derivative of e^x WOULD be x e^(x-1), but only if x were a constant (whioch is never is), e were a variable, and you were differentiating with respect to...
clooneman
Offline
Apr 5, 2004
5:11 pm
7568
... First, rewrite x^(1/x) as e^((ln x)/x) Then differentiate: ((x*(1/x) - (ln x)*1)/x^2) * e^((ln x)/x) = ((1 - ln x)/x^2) * e^((ln x)/x) = x^(1/x) * (1-ln x)...
brianscsmith
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Apr 5, 2004
6:13 pm
7569
Right, I 've found out that d(a^x)/dx = a^x.ln(a). I couldn't be bothered, sorry. I think some of you already have it cracked anyhow....
clooneman
Offline
Apr 5, 2004
7:47 pm
7570
Before I have a stab at it, what the derivative of a^x? I'm too lazy to look it up....
clooneman
Offline
Apr 5, 2004
8:35 pm
7571
a^x.ln(a) Carlos...
Carlos Assale
c_assalebr
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Apr 5, 2004
8:46 pm
7572
A Magic Matrix is a square number array such that the sums of the collums, rows, and diagonals all add to the same number. Prove or disprove there exist an...
bqllpd
Offline
Apr 6, 2004
5:38 am
7573
I've never done this in text, so let me know how it werks out. You have to think of the first thing that comes to mind after the following questions! Scroll...
bqllpd
Offline
Apr 6, 2004
5:41 am
7574
To differentiate y = x^(1/x) we use a process called 'logarithmic differnetiation' Ok i'll explain how it works. 1) Take natural log of both sides ln y =...
Amit
tough_guy_1977
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Apr 6, 2004
7:49 am
7575
Hello, i need urgent help for obtaining the inverse of a matrix with 54 col and 54 rows and the values of the elements are from 10^-2 to 10^60 so when i used ...
sherif helmy
sherif_master
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Apr 6, 2004
7:52 am
7576
The standard technique is to write the matrix on the left side of your paper, and the identity matrix on the right side. Then you go through some strategic...
slim_the_dude
Offline
Apr 6, 2004
2:35 pm
Messages 7547 - 7576 of 13927   Oldest  |  < Older  |  Newer >  |  Newest
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