Newbetuts

If $\{q_\alpha: X_\alpha \to Y_\alpha\}$ is a family of quotient maps, then $q:\coprod_\alpha X_\alpha \to \coprod_\alpha Y_\alpha$ is a quotient map.

Is it okay to reverse engineer proofs in homework questions?

If $A$ and $B$ are matrices such that $AB^2=BA$ and $A^4=I$ then find $B^{16}$.

proof by induction: sum of binomial coefficients $\sum_{k=0}^n (^n_k) = 2^n$ [duplicate]

Infinum & Supremum: An Analysis on Relatedness

Exercise 9, Section 17 of Munkres’ Topology [duplicate]

Prove that $\cot^2{(\pi/7)} + \cot^2{(2\pi/7)} + \cot^2{(3\pi/7)} = 5$

Prove $\sqrt{a} + \sqrt{b} + \sqrt{c} \ge ab + bc + ca$

Show, using the mean value theorem and given $|f(x)-f(y)| ≤ |x-y|^3$ and $x, y ∈ [0,1]$, that $f(x)$ has to be constant. [duplicate]

Prove that f is a constant function

prove $x \mapsto x^2$ is continuous

When has one sufficiently mastered an area of mathematics?

Why does drawing $\square$ mean the end of a proof?

Intuition of Addition Formula for Sine and Cosine

Teacher claims this proof for $\frac{\csc\theta-1}{\cot\theta}=\frac{\cot\theta}{\csc\theta+1}$ is wrong. Why?

Proving $\sum_{i=0}^n 2^i=2^{n+1}-1$ by induction. [duplicate]

Proof of $n^2 \leq 2^n$.

New posts in proof-writing

How do I prove the completeness of $\ell^p$?

Can you use both sides of an equation to prove equality?

Proving the sum of the first $n$ natural numbers by induction [duplicate]

If $\{q_\alpha: X_\alpha \to Y_\alpha\}$ is a family of quotient maps, then $q:\coprod_\alpha X_\alpha \to \coprod_\alpha Y_\alpha$ is a quotient map.

Is it okay to reverse engineer proofs in homework questions?

If $A$ and $B$ are matrices such that $AB^2=BA$ and $A^4=I$ then find $B^{16}$.

proof by induction: sum of binomial coefficients $\sum_{k=0}^n (^n_k) = 2^n$ [duplicate]

Infinum & Supremum: An Analysis on Relatedness

Exercise 9, Section 17 of Munkres’ Topology [duplicate]

Prove that $\cot^2{(\pi/7)} + \cot^2{(2\pi/7)} + \cot^2{(3\pi/7)} = 5$

Prove $\sqrt{a} + \sqrt{b} + \sqrt{c} \ge ab + bc + ca$

Show, using the mean value theorem and given $|f(x)-f(y)| ≤ |x-y|^3$ and $x, y ∈ [0,1]$, that $f(x)$ has to be constant. [duplicate]

Prove that f is a constant function

prove $x \mapsto x^2$ is continuous

When has one sufficiently mastered an area of mathematics?

Why does drawing $\square$ mean the end of a proof?

Intuition of Addition Formula for Sine and Cosine

Teacher claims this proof for $\frac{\csc\theta-1}{\cot\theta}=\frac{\cot\theta}{\csc\theta+1}$ is wrong. Why?

Proving $\sum_{i=0}^n 2^i=2^{n+1}-1$ by induction. [duplicate]

Proof of $n^2 \leq 2^n$.