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visits member for 2 years, 2 months
seen Oct 16 at 7:24

Oct
15
comment How many 6 digit numbers with 2 or 3 repetitions allowed
@calculus sorry for my bad English. I modified the question, maybe this time it is simpler to understand. From 2 repetitions, I tried to mean that every digit (0,..,9) can be used at most 2 times while forming the 6 digit number.
Oct
15
comment How many 6 digit numbers with 2 or 3 repetitions allowed
@CameronBuie yes both of them are true for their cases. sorry for the late reply
Apr
8
comment Combinatorial explanation to following recurrence relation $a_n = 2 a_{n-1} + a_{n-2}$
@xen I did not say azimut's proof is not combinatorial. I just wanted to say it may not be what Xentius looking for according to his previous questions. But of course only one to confirm this is Xentius.
Apr
8
comment Combinatorial explanation to following recurrence relation $a_n = 2 a_{n-1} + a_{n-2}$
I guess what @Xentius meant by a combinatorial proof is not this. He seems to be looking for an answer like in this question he asked: math.stackexchange.com/questions/340905/…
Mar
19
comment Binomial formula for $(x+1)^{1/3}$ (related to Newton's binomial theorem)
@Xentius it's called gamma function.
Dec
16
comment Proof about diameter of a set
I guess this should be enough for a) Choose $x_n ∈ A_n$ , and show that the sequence $(x_n)$ satisfies the Cauchy condition.
Dec
16
comment For which x values, this series is convergent?
@DonAntonio Thank you so much. It is a pleasure for me to be a member of the club. = )
Dec
16
comment For which x values, this series is convergent?
@DonAntonio Ops! you are both right. I edited my answer.
Dec
5
comment Limit proof of $a^n$ where |a|<1
yeah it is so simple. how could not I think that! :/ I guess I need to take a rest. thank you for your answer.
Dec
5
comment Limit proof of $a^n$ where |a|<1
@nikita2 you are right. I edited my question.
Dec
3
comment Boundary and Interior Points of the set: Rational Numbers
@TonyK Oh I guess I understood what you wanted to say. In the interval $(X_0-r,X_0+r)$, there are also irrational numbers and therefore it cannot be a subset of $Q$. Right?
Nov
30
comment Using Euler Phi function to show that there are infinitely many primes
I guess I understood why $\phi(m) = 1$. Any selection of (m,n) will not be relatively prime only (m,1) will be relatively prime hence $\phi(m) = 1$. That is brilliant. Thank you so much.
Nov
30
comment Using Euler Phi function to show that there are infinitely many primes
I guess it must go on like this: we know that $\phi(m) = 1$ however according to the multiplicative property of the phi function, $\phi(m) = (p_1-1)*(p_2-1)*...*(p_k-1)$ which is not clearly equal to 1. However I could not exactly understand why $\phi(m) = 1$. Maybe I should give it some time. = )
Nov
26
comment Infinitely number of primes in the form 4n+1 proof
@GerryMyerson can you show me a way to prove it?
Nov
26
comment Showing that if a subset of a complete metric space is closed, it is also complete
was that all? :D
Nov
26
comment Showing that if a subset of a complete metric space is closed, it is also complete
I am extremely tired so that it has become really hard to think clear, but I added more details about what I have done so far. Could you please take a look and help me to put this proof in a correct shape? Thanks!
Nov
26
comment Two proofs about metric spaces and one about series
@MehenniBenghorbal Oh it just came to my mind: is it OK to directly say that let $\epsilon=\frac{l}{2}$ for a formal proof? I know it does not change anything as long as $\epsilon$>0. But I had a feeling that my professor would not be happy if I directly say let $\epsilon=\frac{l}{2}$. = )
Nov
26
comment Two proofs about metric spaces and one about series
@AndresCaicedo yes I meant to say "it is close to $l$" but now I am aware that that statement was useless.
Nov
26
comment Two proofs about metric spaces and one about series
@amWhy you are right. I was a little bit panicked to get a fast answer that is why I did such a thing. I have already got answers for the first two questions. So I only deleted the third question and will post it as a separate question.
Nov
26
comment Two proofs about metric spaces and one about series
I am very grateful for your help!