New posts in proof-writing

A subset of a compact set is compact?

general-topology proof-writing compactness

Prove that the multiplicative groups $\mathbb{R} - \{0\}$ and $\mathbb{C} - \{0\}$ are not isomorphic.

abstract-algebra group-theory proof-writing proof-verification

How can I simply prove that the pearson correlation coefficient is between -1 and 1?

proof-writing correlation

How to obtain the complete factorization of $P_n(X)=\frac{(X+i)^{2n+1} - (X-i)^{2n+1}}{2i} = 0$

polynomials proof-writing factoring

False proof that $ρe^{iθ} = ρ$ and so complex numbers do not exist? [duplicate]

complex-numbers proof-writing solution-verification exponentiation fake-proofs

Diagonals of quadrilateral $ABCD$ intersect at $E$. Given $\frac{AE}{AC} = λ,\>\frac{BE}{BD} = μ$. Find ratios for sides

geometry proof-writing alternative-proof

Singular value decomposition proof

proof-verification proof-writing proof-explanation least-squares svd

Is it possible for the DNF and CNF to be the same

logic proof-writing propositional-calculus conjunctive-normal-form disjunctive-normal-form

H0w t0 prove that periodic decimal numbers are rational? $a_1...a_k(b_1b_2..b_l)={m \over n}$

proof-writing rational-numbers

Showing that $\lim_{x\to c} f(x) > \alpha \Rightarrow f(c+h) > \alpha$ for $|h| < \delta $ where $\delta > 0 $

limits continuity proof-writing formal-proofs

Prove that a set $E$ is closed iff it's complement $E^{c}$ is open

real-analysis general-topology proof-writing

Is the proof I am using, sufficient/ correct for the system of equation?

algebra-precalculus proof-verification proof-writing contest-math systems-of-equations

Exercise 6, Section 17 of Munkres’ Topology

general-topology proof-writing solution-verification alternative-proof

Stuck with proof for $\forall A\forall B(\mathcal{P}(A)\cup\mathcal{P}(B)=\mathcal{P}(A\cup B)\rightarrow A\subseteq B \vee B\subseteq A)$

elementary-set-theory proof-writing

Show that $\mathbb{R}$ is Hausdorff.

real-analysis general-topology proof-verification proof-writing

Prove that if a function $f$ has a jump at an interior point of the interval $[a,b]$ then it cannot be the derivative of any function.

calculus proof-writing

Proof of Non-Ordering of Complex Field

proof-writing ordered-fields

Proving an infinite number of primes of the form 6n+1

elementary-number-theory proof-writing

Proof of matrix norm property: submultiplicativity

matrices proof-writing normed-spaces

Maps - question about $f(A \cup B)=f(A) \cup f(B)$ and $ f(A \cap B)=f(A) \cap f(B)$

functions elementary-set-theory proof-writing problem-solving