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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.


Oct
15
comment Construction of a random probability measure on the positive integers
Which sort of description do you expect?
Oct
15
revised Finding the value of $f_{x+y}$ for multivariate normal distributon
added 3 characters in body
Oct
15
comment a problem about liminf/ limsup with a continuous function
Reread the question: one assumes that liminf<L<limsup hence one is always in your L∈[a,b] case.
Oct
15
answered How to prove that $a<S_n-[S_n]<b$ infinitely often
Oct
15
comment a problem about liminf/ limsup with a continuous function
Good starting point. Now, can you show that there exists y and z in B(0,1/n) such that f(y)<L<f(z)?
Oct
15
comment Why is $ \left( \frac1n \sum_{i=1}^n x_i^{p+1} \right) \geq \left( \frac1n \sum_{i=1}^n x_i \right)^{p+1} $ true?
@J.J. This might be why the OP is stuck. Yet another example of the "advantage" of putting nothing into a question except its flat statement...
Oct
15
comment a problem about liminf/ limsup with a continuous function
You did? Right, then you will easily add to the question your thoughts and your failed tries about it (a practice which, on this site, is recommended).
Oct
15
answered Why is $ \left( \frac1n \sum_{i=1}^n x_i^{p+1} \right) \geq \left( \frac1n \sum_{i=1}^n x_i \right)^{p+1} $ true?
Oct
15
comment Finding the value of $f_{x+y}$ for multivariate normal distributon
Sure: to go from the first integral to the second one, you replace $f_{X,Y}(x,z-x)$ by $f_X(x)f_Y(z-x)$. This is not kosher since $f_{X,Y}(x,z-x)$ is not $f_X(x)f_Y(z-x)$, as the formula for $f_{X,Y}(x,y)$ at the beginning of your post shows.
Oct
15
comment conversion of discrete to continuous
Of course there are plenty of functions $n(\ )$ such that $n(j)=N_j$ for every integer $j$, but this one seems rather natural, no?
Oct
15
comment probability question show that $P(A)>P(B)$
I answered this quite recently--Oh well...
Oct
15
answered Finding the value of $f_{x+y}$ for multivariate normal distributon
Oct
15
comment Conditional expected value of a product of two independent normal variables
Trying to find $t$ such that $(z,t)$ is independent gaussian is natural. The rest follows.
Oct
15
comment Show a stochastic process is a martingale using Ito's lemma
Added \langle and \rangle (hope you don't mind) and upvoted (hope you don't mind either...).
Oct
15
revised Show a stochastic process is a martingale using Ito's lemma
added 13 characters in body
Oct
15
answered recurrence relations substitution method
Oct
15
revised The limit of $\sin(n^\alpha)$
edited title
Oct
15
comment conversion of discrete to continuous
You mean, how to go from $(1+k)^j$ to $(1+k)^t$? Hmmmm...
Oct
15
comment Asymptotic behaviour of a function of a bivariate normal vector
You are welcome.
Oct
15
comment Existence of non-trivial solutions for $Ax=0$
(singularity-theory) refers to something completely different.