Is irrational times rational always irrational?
32848
Prove that the product of a non-zero rational and irrational number is irrational.
151325
(How to/Can I) show irrational numbers?
35837
How to prove that any (integer)$^{1/n}$ that isn't an integer, is irrational?
87596
Is $\sum_{p}\frac{1}{p^{2}}$ irrational?
67605
Different proof that $\sqrt{2}$ is irrational
23164
Why are irrational numbers uncountable and rationals countable?
87410
Are there real numbers that are neither rational nor irrational?
19076
If a.b.c,d are rationals and x is irrational number, then prove that $\frac{ax+b}{cx+d}$ is usually a irrational number. When do exceptions occur?
64885
Irrational and rational sequence proof
120906
Is there a proof that $\pi \times e$ is irrational?
106242
Why no common factors in proving root 2 is irrational?
5529
Proving that $x$ is irrational if $x-\lfloor x \rfloor + \frac1x - \left\lfloor \frac1x \right\rfloor = 1$
13592
How can $\pi$ be irrational if it can be calculated using an infinite series of rational numbers?
86988
Cardinality of the Irrationals
24706
Is there a rational number between any two irrationals?
117366
Is there a simple, constructive, 1-1 mapping between the reals and the irrationals?
44573
Can $\pi$ be rational in some base radix