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Alex

Just getting back to programming, learning opensource stuff and maybe C#

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194
Too old to start math
math.stackexchange.com

35
How to prove that $\lim\limits_{x\to0}\frac{\sin x}x=1$?
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17
Expectation on 1/X
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16
What does the value of a probability density function (PDF) at some x indicate?
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14
How to determine equation for $\sum_{k=1}^n k^3$
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11
Sum of Square roots formula.
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10
What is $\int\frac{dx}{x+\sqrt{1-x^2}}$?
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10
How do I find the cumulative distribution function of a binomial random variable?
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10
What is an intuitive approach to solving $\lim_{n\rightarrow\infty}\biggl(\frac{1}{n^2} + \frac{2}{n^2} + \frac{3}{n^2}+\dots+\frac{n}{n^2}\biggr)$?
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9
Flip a fair coin until three consecutive heads or tails appear
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9
Probability of questions being on an exam
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9
How to derive the closed form of the sum of $kr^k$
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9
Approximate $\sqrt{e}$ by hand
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8
How to compute $\sum_{n=1}^\infty{\frac{n}{(2n+1)!}}$?
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8
When is a Markov chain null recurrent?
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8
How to differentiate $y=\sqrt{\frac{1+x}{1-x}}$?
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8
Linear combination of independent poisson random variables
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8
How do I find $\lim_{x\rightarrow \infty} x\sin \frac {c}{x}$?
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7
How many distinct permutations of the string "NADAMADRID" have the word DAM appearing in them?
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7
Find the values of α and β for which this series converges.
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7
Why do I get one extra wrong solution when solving $2-x=-\sqrt{x}$?
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7
Find $\lim\limits_{x \to \infty} \left(\sqrt{x^2+x+1} - \sqrt{x^2-x} \right)$
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7
If $\sum a_n$ with $a_n>0$ is convergent, then is $\sum {a_n}^2$ and $\sum \sqrt{a_n}$ always convergent?
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7
Infinite sum of logarithms
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7
Why is the expected number coin tosses to get $HTH$ is $10$?
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7
Binomial theorem for non integers ? O_o ??
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6
Collection of surprising identities and equations.
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6
Calculate $\sum_{k=1}^n \frac 1 {(k+1)(k+2)}$
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6
Solving a recurrence relation, $a_n = \sqrt{n(n+1)}a_{n-1} + n!(n+1)^{3/2}$
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6
Dividing coins between two people
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