New posts in alternative-proof

Easy proof for sum of squares $\approx n^3/3$

sequences-and-series limits alternative-proof

Lesser known derivations of well-known formulas and theorems

alternative-proof

Showing that the minimal polynomial of an $n \times n$ matrix has degree at most $n$ without using the Cayley-Hamilton Theorem

linear-algebra modules alternative-proof minimal-polynomials

Alternate proof for $a^2+b^2+c^2\le 9R^2$

geometry inequality triangles alternative-proof geometric-inequalities

How to deduce open mapping theorem from closed graph theorem?

functional-analysis banach-spaces alternative-proof

Crux problem #33 with vector approach

geometry vectors euclidean-geometry alternative-proof

$\operatorname{Aut}(S_4)$ is isomorphic to $S_4$

group-theory alternative-proof symmetric-groups

Proof that negative binomial distribution is a distribution function?

probability-theory probability-distributions alternative-proof

Visualization of surface area of a sphere

geometry education alternative-proof

questions about Rudin's summation by parts

alternative-proof solution-verification

Group presentation of $A_5$ with two generators

abstract-algebra group-theory alternative-proof symmetric-groups group-presentation

Can $\lim_{h\to 0}\frac{b^h - 1}{h}$ be solved without circular reasoning?

calculus limits logarithms exponential-function alternative-proof

Proving that $\int_0^1 \frac{\ln(x)+\ln(\sqrt x+\sqrt {1+x})}{\sqrt {1-x^2}} dx=0$

calculus integration definite-integrals alternative-proof

Prove a trigonometric identity: $\cos^2A+\cos^2B+\cos^2C+2\cos A\cos B\cos C=1$ when $A+B+C=\pi$

geometry trigonometry alternative-proof substitution

If $q^k n^2$ is an odd perfect number with special prime $q$, then $n^2 - q^k$ is not a square.

number-theory elementary-number-theory alternative-proof solution-verification perfect-numbers

Proving a function $\frac{1}{2y}\int_{x-y}^{x+y} f(t) dt=f(x)$ is a linear polynomial

real-analysis integration proof-verification alternative-proof

Geometry: Prove that two angles are not equal

geometry alternative-proof

Is it possible to utilize the convergence of the sequence $z_{n+1}=a/(1+z_n)$ to prove that the sequence $x_{n+2} = \sqrt{x_{n+1} x_n}$ is convergent?

real-analysis sequences-and-series convergence-divergence alternative-proof

Pólya and Szegő, Part I, Ch. 4, 174.

sequences-and-series problem-solving alternative-proof

If the Greeks had been four dimensional, would they have been able to derive the pi squared coefficient for the hypersphere volume without calculus?

geometry euclidean-geometry volume alternative-proof spheres