New posts in algebra-precalculus

Sum of roots of a functional equation

How to solve a quartic equation?

Prove $3^n = \sum_{k=0}^n \binom {n} {k} 2^k$

How to interpret 2 variables separated by a comma in chained inequalities

Assuming the existence of solutions in solving exercises

How many solutions for this equation?

How to solve these $3$ equations for three unknowns $x$,$y$,$z$? [duplicate]

epsilon Delta approach in Proving $\lim_{x \to 8} \sqrt[3]x=2$

How to prove $(6666\ldots66)^2 + 8888\ldots88 = 4444\ldots44$ (with $n$ 6s and 8s, $2n$ 4s)

If $x+y+z=xyz$, prove $\frac{2x}{1-x^2}+\frac{2y}{1-y^2}+\frac{2z}{1-z^2}=\frac{2x}{1-x^2}\times\frac{2y}{1-y^2}\times\frac{2z}{1-z^2}$ [duplicate]

An incorrect method to sum the first $n$ squares which nevertheless works

If $x$ and $y$ are rational numbers and $x^5+y^5=2x^2y^2,$ then $1-xy$ is a perfect square.

a circle graph is not a function?

Function that looks a lot like exponential, but isn't

Is a function periodic $f(x) = \cos (x) +\cos(x^2)$

$\dfrac{pq}{r}+\dfrac{qr}{p}+\dfrac{pr}{q}\in\Bbb Z\,\Rightarrow\, \dfrac{pq}{r},\dfrac{qr}{p},\dfrac{pr}{q}\in\Bbb Z$

Solve the equation: $x=\sqrt{a-\sqrt{a+x}},(a\geq 1)$

Average of age in a family

Is it possible to shorten the solution for this 2014 RMO question?

Why does two terms immediately adjacent "mean" multiply?