Rational with minimal denominator between two rationals
103744
Minimal $ab$ for Rational Number $a/b$ in an Interval
12701
Perfect set without rationals
84374
Rational function with absolute value $1$ on unit circle
95294
Dense subset of $C[0,1]$ which preserves rationals
75349
Minimal polynomial of $\sqrt[3]{2} + \sqrt{3}$
102583
Infinite number of rationals between any two reals.
99366
Minimum of an expression involving radicals: $\sqrt{\frac{2a}{a+b}} + \sqrt{\frac{2b}{b+c}} + \sqrt{\frac{2c}{c+a}}$
24706
Is there a rational number between any two irrationals?
132931
Determining the parity of the coefficients of a quadratic given that there is a rational solution
117366
Is there a simple, constructive, 1-1 mapping between the reals and the irrationals?
143541
Decomposition of an algebraic number into a sum or product of algebraic numbers with smaller degree
39621
Let a, b, c, d be rational numbers...
87131
Discontinuous at rationals and differentiable at irrationals?
101372
Questions concerning smallest fraction between two given fractions.
67161
No maximum(minimum) of rationals whose square is lesser(greater) than $2$.
30523
A binary irrational with bits defined by primes
53411
Minimum of $\sqrt{\frac{a}{b+c}}+\sqrt{\frac{b}{c+a}}+\sqrt{\frac{c}{a+b}}$