# Questions tagged [elementary-proofs]

For questions related to 'elementary' proofs in a technical sense, which has nothing to do with the difficulty of the argument or result. A typical example would be 'elementary' proofs of the Prime Number Theorem, which avoid complex analysis. The tag is however not limited to this particular notion of 'elementary.'

**3**

**1**answer

### Two conjectural infinite series for $\pi$

**0**

**0**answers

### Pseudo-Droz-Farny circles

**8**

**1**answer

### A conjectural infinite series for $\frac{\pi^2}{5\sqrt{5}}$

**6**

**2**answers

### An infinite series involving the mod-parity of Euler's totient function

**8**

**1**answer

### An infinite series involving harmonic numbers

**4**

**1**answer

### Lemoine-Lozada circles

**3**

**0**answers

### Four infinite series involving Riemann zeta function

**12**

**1**answer

### The 4th vertex of a triangle?

**5**

**2**answers

### The 4th Lemoine circle

**5**

**3**answers

### An infinite series that converges to $\frac{\sqrt{3}\pi}{24}$

**12**

**1**answer

### Nonstandard proofs of the fundamental theorem of arithmetic

**1**

**1**answer

### Collinearity in tangential pentagon

**3**

**1**answer

### The product of the lengths of two line segments that belong to Newton line

**5**

**1**answer

### The square root of natural number expressed by an infinite series

**4**

**1**answer

### The constant $\pi$ expressed by an infinite series

**4**

**1**answer

### The constant $e$ represented by an infinite series

**4**

**2**answers

### Six conelliptic points

**3**

**1**answer

### Three circles meet at a point

**2**

**0**answers

### Principal diagonals of octagon meet in a single point

**1**

**0**answers

### How to estimate the highest power of 2 in the partial sum of 2-adic $\log(-1)$ (i.e. $\sum_{i=1}^n\frac{2^i}{i}$)?

**1**

**1**answer

### Generalizing Bottema's theorem

**3**

**1**answer

### Equal sums of line segments

**6**

**3**answers

### Necessary and sufficient condition for quadrilateral to be cyclic

**6**

**2**answers

### Three circles intersecting at one point

**2**

**1**answer

### Collinearity of three significant points of bicentric pentagon

**2**

**0**answers

### Polyhedron - sphere intersection

**11**

**3**answers

### What is the limit of $a (n + 1) / a (n)$?

**4**

**1**answer

### Collinearity in bicentric polygons

**6**

**1**answer

### Necessary and sufficient condition for tangential polygon to be cyclic

**2**

**1**answer

### Stability estimates on quotients of the form $ \frac{\prod_{j=1}^n a_j}{\prod_{j=1}^n b_j} $

**4**

**1**answer

### Point of concurrency [closed]

**9**

**2**answers

### A tricky integral to evaluate

**1**

**1**answer

### A binomial convolution of Catalan numbers vs "utterly odd numbers"

**28**

**1**answer

### Functional-analytic proof of the existence of non-symmetric random variables with vanishing odd moments

**1**

**1**answer

### A generalization of Harcourt's theorem

**1**

**1**answer

### A formula for the area of bicentric quadrilateral

**1**

**1**answer

### A new perspective on Lehmer's totient problem

**2**

**1**answer

### The centroid, the first and second Napoleon points and $X(930)$ lie on a circle

**2**

**1**answer

### Four concyclic triangle centers

**51**

**5**answers

### What is the simplest proof that the density of primes goes to zero?

**1**

**1**answer

### A generalization of Napoleon's theorem

**2**

**2**answers

### Six concyclic points

**2**

**2**answers

### Four concyclic points inside bicentric quadrilateral

**14**

**2**answers

### Euclid-style proof of Dirichlet’s theorem on primes in certain arithmetic progression

**14**

**4**answers

### Six points on an ellipse

**11**

**1**answer

### Intersection point of three circles

**13**

**6**answers

### Alternative proofs sought after for a certain identity

**-4**

**2**answers

### An elementary-looking integral inequality

**2**

**0**answers

### Asking for a combinatorial proof of a binomial-sum

**3**

**2**answers