Reputation
Next privilege 2,500 Rep.
Create tag synonyms
Badges
8 20
Newest
 Informed
Impact
~23k people reached

  • 0 posts edited
  • 0 helpful flags
  • 143 votes cast
Mar
15
revised Prove that there exists a choice of $\pm$ signs
deleted 4 characters in body
Mar
14
answered Prove that there exists a choice of $\pm$ signs
Mar
13
comment Evaluating the integral $\int \frac{1}{x+ \text{ ln }(x)}dx$
wolframalpha.com/input/…
Mar
13
comment The formula of Eclidean distance to a hyperplane.
If you consider $H$ as a hyperplane in $\mathbb{R}^{mn}$ and $X$ and $Y$ are two coordinates (i.e. $X,\,Y\in\mathbb{R}$), then $mn$ real numbers, not just $X$ and $Y$, are necessary to specify a point in $\mathbb{R}^{mn}$.
Mar
12
answered Positive numbers inequality
Mar
12
comment Weaker version of the A.M.-G.M. inequality
Related: mathoverflow.net/questions/122411/…
Mar
12
comment Positive numbers inequality
The above answer can be rescued if you show $\sum iy_i\ge \sum i\cdot\frac1n$ when $0< y_1\le y_2\le \cdots \le y_n$ and $y_1+\cdots+y_n=1$.
Mar
11
comment Positive numbers inequality
Where did you use $y_1\le y_2\le \cdots \le y_n$? and why is $\left(\frac2{n(n+1)}\sum y_i\right)^{\log_2 3}\ge \frac1{n^2}$ (the last inequality)?
Feb
17
comment prove that $f_n = 37111111…111$ is never prime
Try Factor[371], Factor[3711], Factor[37111] etc. (up to $n=10$) with WolframAlpha.
Feb
17
comment common probability
Was your sampling not repeated? The above data only suggest that the data from the lab and that from the field are different. Are there any reasons for believing that they are "same things"?
Feb
14
comment Solving a system of equations with an inequality constraint
What sort of functions are $f_1$, $f_2$ and $f_3$?
Feb
13
comment Model a chemical phenomenom
Yes, periodic boundary conditions are often used in mathematical / physical modeling and are a good starting point.
Feb
12
comment Model a chemical phenomenom
I think the lattice should reflect the actual shape of the receptor, but you could start with a rectangle (if it's 2D) or a cuboid (if it's 3D).
Feb
11
answered Model a chemical phenomenom
Feb
10
comment Express $\binom{n+2}{k}$ according to $\binom{n}{k}$
Similar question: math.stackexchange.com/questions/649567/…
Feb
9
awarded  Informed
Feb
9
answered Showing the “only if” direction of equality in a complex equality
Feb
6
answered A reccurent sequence
Feb
5
revised Find one solution for system of inequalities (if exits)
deleted 194 characters in body
Feb
5
comment Hard inequality with conditions
Then you can construct a counterexample easily, following the above argument. (such as in the case $b_2/g_2=r_2>1$ and $b_3/g_3=r_3<1$)