Intereting Posts

Evaluating $\int\sqrt{\frac{1-x^2}{1+x^2}}\mathrm dx$
Prove that if $n$ is composite, then $(n-1)! \equiv 0 \pmod n$
Convergence of characteristic functions to $1$ on a neighborhood of $0$ and weak convergence
Triangular Factorials
Does equicontinuity imply uniform continuity?
Lebesgue density theorem in the line
Conditions for intersection of parabolas?
Problem in Jacobson's Basic Algebra (Vol. I)
Complement of a set and inverse image.
Metrizable compactifications
Suppose $A^n = 0$ matrix for some $n > 1$. Find an inverse for $I – A$.
what does ∇ (upside down triangle) symbol mean in this problem
can we use generating functions to solve the recurrence relation $a_n = a_{n-1} + a_{n-2}$, $a_1=1$, $a_2=2$?
Metric of the flat torus
Convolution of half-circle with inverse

Let $X$ be the set of natural numbers $k_i$, $k_i \geq 1$, with the property that at least one of the equations $p_i = $6$ k_i \pm 1$ gives the $i$-th prime number (disregarding $2$ and $3$), and define the set $Y$ to be $Y = \mathbb{N} \setminus \{1\}$. Is it true that each element of Y can be represented as $2 k_i$ or as the sum $k_i + k_j$, where $k_i$ and $k_j$ are both elements of set X?

- Make up a reasonable definition for the bipartite complement of a bipartite graph
- How many arrangements of the letters in the word CALIFORNIA have no consecutive letter the same?
- Information captured by differential forms
- Sum of numbers on chessboard.
- Why is it that if I count years from 2011 to 2014 as intervals I get 3 years, but if I count each year separately I get 4 years?
- Number of decompositions of 20 into four integer parts
- A set of integers whose elements all divide $2015^{200}$ but do not divide each other
- Combinatoric in binary sequence
- Can the Basel problem be solved by Leibniz today?
- The number of ways to write a positive integer as the sum of distinct parts with a fixed length

This statement is implied by Goldbach’s Conjecture, and does not look to be much easier to prove than the conjecture itself.

- What is the fallacy of this proof?
- Understanding the trivialisation of a normal bundle
- Finding inverse of polynomial in a field
- How to find ${\large\int}_0^1\frac{\ln^3(1+x)\ln x}x\mathrm dx$
- Maximizing the trace
- Examples of Non-Noetherian Valuation Rings
- Is the topology of the p-adic valuation to the unramfied extension discrete?
- Why do we do mathematical induction only for positive whole numbers?
- Example of a non-Noetherian complete local ring
- Help with Cartesian product subsets
- Prove $\varphi\in\mathcal{S}(\mathbb R^n)$ if and only if the following inequality holds..
- Why do those terms vanish if the metric is Hermitian?
- Set Theoretic Definition of Numbers
- Product of quotient map a quotient map when domain is compact Hausdorff?
- Show that a representative function on a profinite group factor through a surjection