New posts in Solution Verification

Show that C is a circle and find its radius and centre.

If $\sum_{n=1}^\infty\vert a_{n+k}-a_n\vert<\infty$, then $\{a_n\}_{n=1}^\infty$ has a convergent subsequence

An Olympiad geometry question on area lemma.

Triple summation verification $\sum_{1\le i\lt j\lt k}\frac{1}{2^i3^j5^k}$

Is my solution correct in terms of proof? I can't prove directly that $f(x)=4$.

What is wrong with this proof that inaccessible cardinals are inconsistent

Indian National Olympiad $2000$ Problem $6$

Proof Verification of $|\cos(a) - \cos(b)| \leq |b-a|$

Abel criterion proof

Does $\sum\limits_{k=1}^{n}\frac{(-1)^k}{k}(-1)^n$ converge?