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As somebody used to say:

Does research. Smokes. Battles administration. Smokes. Wishes he could stop battling administration so that he could have more time to do research. Smokes some more.

The same. Except I do not smoke.


How to ask a good question?

This paragraph is for my personal use but freely available:

Welcome to Math.SE! Please, consider updating your question to include what you have tried and where you are getting stuck. That way, people on this site will know exactly what help you need.


1d
comment How central limit theorem invoke two random variables jointly Gaussian or independent?
They are not necessarily.
1d
comment Prove that the real part of every non-trivial zero of the Riemann zeta function is 1/2.
Tongue-in-cheek question, perhaps? Voting to close.
1d
comment Conditional Distribution: how to set up Limit of Integration of a joint density
Not sure I get your point. Recall that a distribution is fully characterized either by its CDF or, when its PDF exists, by its PDF. Hence the PDF is at least as qualified as the CDF to describe a given distribution. Actually, except in some introductory probability classes, mathematicians use PDFs rather than CDFs (as soon as the PDF exists, of course).
1d
answered Does $\sum\limits_{k=1}^\infty |\sin(ak)/k|$ converge?
1d
revised Does $\sum\limits_{k=1}^\infty |\sin(ak)/k|$ converge?
added 1 character in body; edited title
1d
comment Expected value of maximum of two random variables from uniform distribution
Starting from line -2, this should read $\frac16+\frac16=\frac13$, which is not the correct result. The mistake is at line -4, as described by user @jscg.
1d
comment Sum of two random variable X and -X
@user2770287 Can you? Then, how? (And if you can, your question is solved.)
1d
comment Sum of two random variable X and -X
Surely the argument in your (Graham) last comment is wrong. One cannot choose any random variables W and Z with the prescribed distributions and hope that Z+W is related to X+Y. And since the whole solution relies on this argument, this is annoying...
1d
comment How to develop a probability distribution/density function of an issue?
Thus: case closed?
1d
comment \lim_{n\to ∞}c_n * a_n = 0
Provided the limit in the middle exists, which is kind of the main point of these exercises.
1d
comment Conditional Distribution: how to set up Limit of Integration of a joint density
Why is $x^2+y^2$ in $f(x,y)$ becoming $x^2-y^2$ in $f_{Y|X}(y|x)$? // Why is giving $f_{Y|X}$ not sufficient to answer the question "Find the conditional distribution"?
1d
comment Conditional Distribution: how to set up Limit of Integration of a joint density
Let me suggest to avoid the abuse of notation in your own answer (at line -3).
1d
comment ODE system and Lie symmetries
Of course, one line of algebra allows to show that (ODE_1)+(ODE_2)+(SYM) implies (*). Is this what you are after?
1d
comment How find this the expected number of games played, if A won $n$ consecutive games?
To add a version of the question in Chinese, add it to the question, not in the comments.
1d
answered How find this the expected number of games played, if A won $n$ consecutive games?
1d
comment How to show the equation $x^4 + 2cx^3 + 6x^2 + 60x =-11$ has exactly two real solutions?
Better now (even though the inequalities are not strict).
1d
revised Layman perspective of mean time spent in transient state of a Markov chain.
added 23 characters in body
1d
comment Expected Value of Matches Played Between Two Teams
@eaxdpiotnyeantial "why t(..)=1+0.5t(..)" Well, what can I say? This is the point of the whole answer to explain why. "and how did you checked your result" I did not, I provided a formula for the OP to check their own computations against it. "and why isn't the answer... 18" Why should it? Note that every series lasts at least 4 games and at most 7 games hence a mean number of games per series of 18 would be surprising.
1d
revised A basic question on the existence of expectation?
deleted 45 characters in body
1d
comment Exponential distribution.Bank waiting time
"For (a) I tried doing something like P(x" Suspense...