Reputation
6,338
Top tag
Next privilege 10,000 Rep.
Access moderator tools
Badges
6 27 86
Impact
~142k people reached

May
17
accepted Having the roots of a polynomial, is it possible to go back and find a polynomial that have exactly these roots?
May
14
accepted How to show that $at^2+bt+c$ can be written as $\displaystyle \begin{equation} a \left( t+\frac{b}{2a}\right) ^2-\frac{1}{4a}(b^2-4ac)\end{equation}$?
May
14
accepted What is $R(k,l)$?
May
6
accepted Is there a problem in assuming that a point is the same thing of a vector?
Apr
20
accepted Identify the subset of the plane composed by $R\cos \theta=5$ by means of polar coordinates $R,\theta$?
Apr
20
accepted Why $-1 \leq\frac{\langle A,B\rangle}{||A||\, ||B||}\leq1$?
Apr
12
accepted Prove that $(A,B)\sim(P,Q)$ and $(C,D)\sim (P,Q)\implies (A,B)\sim (C,D)$?
Apr
6
accepted Equations of the tangent lines of $y=x^4$ at the point $(2,0)$?
Apr
2
accepted How to show that $\frac{-1}{x^2}=0$ has no solutions?
Apr
2
accepted Are there two meanings to induction?
Feb
16
accepted $4$ judges must distribute grades from $1$ to $6$ for each participant. In how many ways one can score $22$ points?
Feb
9
accepted How to obtain the chromatic polynomial of $C_5$?
Feb
9
accepted What is the connection with $g=1+\frac{1}{g}$ and $G_n= 1+\frac{1}{G_{n-1}}$?
Feb
8
accepted Find the number of ways to obtain a total of $15$ points by throwing $4$ different dice?
Feb
7
accepted What is the need of exponential generating functions on combinatorial problems?
Feb
1
accepted What is $\langle I\rangle$ in this text?
Jan
28
accepted Confusion about Hajós construction?
Jan
27
accepted What is this binding function?
Jan
13
accepted Why the sequence generated by $x+e^x$ is $(1,x,\frac{x^2}{2!},\frac{x^3}{3!},\frac{x^4}{4!}\ldots)$?
Jan
7
accepted Why is it important to have the closed form of a generating function?