Voyska
Reputation
7,528
Next privilege 10,000 Rep.
Access moderator tools
 Mar 8 accepted When is an upper triangular matrix invertible? Jan 12 accepted What's the importance of conics and quadrics in the context of a course of pure mathematics? Nov 22 accepted How did he went from $b_{12}$ to $\tan 2\varphi=\cfrac{2a_{12}}{a_{11}-a_{22}}$? Nov 19 accepted What is the meaning of primes here? Nov 5 accepted Find the points on the ellipse $x^2+2y^2=1$ where the tangent line has slope $1$. Oct 12 accepted Is my proof of $-(-a)=a$ correct? Sep 8 accepted Prove that the biscetors of adjacent suplementary angles are perpendicular? Sep 3 accepted What's the necessary condition for that any three vectors are parallel to the edges of a triangle in the plane? Sep 3 accepted $1+2+3=\int_{0}^{\infty}t^3e^{-t} dt$? Sep 3 accepted Why the Ramsey number $R(2,4)$ is not equal to $2$? Aug 31 accepted Is non-paralellism transitive? Jul 21 accepted Minor mistake computing $\int \frac{1}{x^3+2x^2-3x} \; dx$? Jul 17 accepted Why $\frac{1}{9}$ becomes $\frac{1}{3}$ in $\frac{1}{3} \int \frac{1}{s^2+1} \, ds$? Jul 7 accepted When should I shift $a$ and $b$ in $\cfrac{x^2}{a^2}+\cfrac{y^2}{b^2}=1$? Jul 7 accepted Where are these choices of $A',B',C'$ for this quadratic form? Jul 1 accepted Why $\int_c^{x+h}f(t) dt-\int_c^x f(t) dt = A(x+h)-A(x)$? Jun 28 accepted A $X \subseteq \mathbb{A}^n$ such that $I(X) \neq I(V(I(X)))$? Jun 20 accepted Confusion in the proof of the derivative of $u(x)/v(x)?$ Jun 19 accepted Why the distance from the point to the line is $\frac{|(P-Q)\cdot N|}{\|N\|}$? Jun 13 accepted Why $u(x+ \Delta x)\cdot v(x+ \Delta x)=(u+\Delta u)(v+\Delta v)$?