2,290 reputation
315
bio website marocprepa.com
location Salé, Morocco
age
visits member for 2 years, 7 months
seen 9 hours ago

Teacher of mathematics in preparatory classes for engineering schools, center of Salé, Morocco.

I just discovered this site and I see an excellent way to:

  • Improve my knowledge.

  • Find sources which are used to make exercises for my students.

  • Meet famous professors and students from various countries of the world.

  • Help by giving answers or comments when I can.

I note that my mother tongue is Arabic, so if I speak bad English, all corrections of my mistakes will make me happy.


19h
comment Zero variance Random variables with density
@jameselmore : If $X$ is a r.v. with density $f$, then $p(X=m)=\int_m^m f(t) dt=0$. Is'nt true ?
21h
asked Zero variance Random variables with density
Dec
29
comment About a limit with Euler $\Gamma$ function.
it's awesome work Felix! Thank you!
Dec
29
accepted About a limit with Euler $\Gamma$ function.
Dec
29
comment About a limit with Euler $\Gamma$ function.
@Mhenni: There is my solution about the limit of $G$ :Let use put: $F(x)=\int_x^{+\infty} t^{x-1} e^{-t} dt$ and: $u=\frac{t}{x}.$ That gives : $F(x)= x^x \int_1^{+\infty}u^{x-1}e^{-ux} du$. If $x > 1$ then: $F(x) \geq x^x \int_1^{+\infty}e^{-ux} du =x^{x-1}e^{-x} \to +\infty$ when $x \to +\infty$.
Dec
29
reviewed Approve In base 10, $101 \times 12 = 1212,$ $1001\times 326 = 326326$ Does these numbers have a name in any base?
Dec
29
comment About a limit with Euler $\Gamma$ function.
@Felix : It is for me to thank you. You gave me the key to my search.
Dec
29
reviewed Approve How to evaluate $\int_{0}^\infty \frac{{x^2}}{e^{\beta {\big(\sqrt{x^2 + m^2}}- \nu\big)} + 1} dx$
Dec
29
reviewed Approve Smallest angle to turn
Dec
29
reviewed Approve Why there are two different values of θ for same quadrant?
Dec
29
comment About a limit with Euler $\Gamma$ function.
@Mhenni: Please see this: cs.purdue.edu/homes/wxg/selected_works/section_02/068.pdf It gives $\frac 12$ as value of this limitn as sos440 in comment above.
Dec
29
comment About a limit with Euler $\Gamma$ function.
Why this paper gives $\frac 12$? See pages 468 and 469. cs.purdue.edu/homes/wxg/selected_works/section_02/068.pdf
Dec
29
comment About a limit with Euler $\Gamma$ function.
@Mhenni:Thank you, i well verify this.
Dec
29
comment About a limit with Euler $\Gamma$ function.
@Mhenni: if you mean the two fuctions $F=\frac 1{\Gamma}$ and $G:x \mapsto \int_x^{+\infty} t^{x-1}e^{-t} dt$ , it is known that $\displaystyle \lim_{+\infty} F = 0$ and i think we can prove that: $\displaystyle \lim_{+\infty} G=+\infty $ ...
Dec
29
reviewed Approve If $m$, $n$, $ p$, and $q$ are positive integers with $m<n$ and $p<q$, then $n^2+m=q^2+p$ if and only if $m=p$ and $n=q$
Dec
29
asked About a limit with Euler $\Gamma$ function.
Dec
9
reviewed Approve Verify question about complements
Dec
9
awarded  Caucus
Dec
1
comment A4 has no subgroup of order 6
an other way : $\mathcal A_4$ has 8 as number of it's 3-cycles.
Nov
4
comment Intro to Proofs: Continuity
Yes: if $\varepsilon > 0$, take $\delta=\frac{\varepsilon}{c}$