How come $\lim_{n\rightarrow \infty} \frac{a_n}{a

Find $f$ such that $(f(x))^2 \ge f(x + y)(f(x) + y), \forall x, y$

Is there another topology on $\mathbb{R}$ that gives the same continuous functions from $\mathbb{R}$ to $\mathbb{R}$?

Verify my understanding of a math joke.

Does there exist a Hamel basis $\mathcal B$ for $\mathbb R$ over $\mathbb Q$ such that $a,b \in \mathcal B \implies \dfrac ab \in \mathcal B$?

How to solve this determinant equation in a simpler way

Example of a very simple math statement in old literature which is (verbatim) a pain to understand

If $28a + 30b + 31c = 365$, then what is the value of $a +b +c$?

Why don't logarithms work here?

Find $x$ and $y$ where $20!=\overline{24329020081766xy\dots}$

Prove that if integral of a squared function is zero, then function is zero function

Calculating the scale factor to resize a polygon to a specific size

Why does universal generalization work? (the rule of inference)

How come $\lim_{n\rightarrow \infty} \frac{a_n}{a_{n-1}}$ be different than 1?