New posts in proof-writing

A set $A \subseteq \mathbb{R}$ is closed if and only if every convergent sequence in $\mathbb{R}$ completely contained in $A$ has its limit in $A$

real-analysis proof-writing

Proving that a list of perfect square numbers is complete

number-theory proof-writing elliptic-curves square-numbers

Finite Sets, Equal Cardinality, Injective $\iff$ Surjective.

functions proof-verification elementary-set-theory proof-writing

Good book for learning and practising axiomatic logic

logic reference-request proof-writing book-recommendation nonclassical-logic

Is collapsing considered a legitimate proof?

sequences-and-series proof-writing

Proving $A \cup (B \cap C) = (A \cup B) \cap (A \cup C)$.

elementary-set-theory discrete-mathematics proof-writing

Prove $e^{\ln{x}} = x$

proof-writing logarithms

If $f: A\rightarrow B$ and $g: B\rightarrow C$ are surjective, then $g\circ f$ is surjective.

functions proof-writing solution-verification function-and-relation-composition

How many values of $x$ are there such that $\sqrt{x(x+p)}$ is a positive integer for some $p$?

elementary-number-theory proof-writing alternative-proof

Proof that a nonzero point is continuous for g(x)

calculus continuity proof-writing

Is there a standard name for this "continuous induction" principle?

proof-writing induction article-writing

New Proof of Pythagorean Theorem (using inscribed circle)?

geometry proof-verification proof-writing circles

Prove : Let A be a set. Then there is a set B such that B /∈ A.

proof-writing solution-verification set-theory

Proof of the Pythagorean Theorem via $\frac{d}{dx}\sin^2 x + \frac{d}{dx}\cos^2 x = 0$

calculus geometry proof-writing

The set of all finite subsets of the natural numbers is countable [duplicate]

elementary-set-theory proof-writing proof-verification

$\epsilon$-$\delta$ limits of functions question

calculus limits proof-writing

Lebesgue - Radon - Nikodym Theorem: Question about $\sigma$-finite case

real-analysis measure-theory proof-writing solution-verification

What are the most popular techniques of proving inequalities?

inequality proof-writing proof-explanation book-recommendation cauchy-schwarz-inequality

A visually guided proof of the fundamental theorem of algebra?

abstract-algebra polynomials complex-numbers proof-writing roots

Determinant of a companion matrix

linear-algebra matrices proof-writing determinant companion-matrices