Where does rationality break in the Leibniz formula for π?
13592
How can $\pi$ be irrational if it can be calculated using an infinite series of rational numbers?
125812
Is sin(x) necessarily irrational where x is rational?
15330
Double limit of $\cos^{2n}(m! \pi x)$ at rationals and irrationals
147410
ArcTan(2) a rational multiple of $\pi$?
30333
Why does Mathematica not restrict the domains of Rational Expressions?
7500
$\arctan$ of a square root as a rational multiple of $\pi$
44400
$e^{2\pi i x} = (e^{2\pi i})^x$: What happens if x is rational?
151439
$\sqrt{1-x^2}$ is not a rational function
23752
Proving Irrationality
122226
Incorrect logic in popular proof of the irrationality of $\sqrt2$?
67031
use contradiction to prove that the square root of $p$ is irrational
49444
Why isn't $e^{2\pi xi}=1$ true for all $x$?
110602
A nasty integral of a rational function
137030
Why are there more Irrationals than Rationals given the density of $Q$ in $R$?
87743
Is a function whose derivative vanishes at rationals constant?
95702
Remarkable/unexpected rational numbers
10008
Proof that the nth root of a rational s/t is irrational unless s and t are perfect nth powers