Archives
- 22 Jun Triangles
- 22 Jun Primes
- 02 Jun Orders
- 02 Jun Gauss's lemma
- 20 Apr Chinese remainder theorem
- 16 Apr System of equations
- 16 Apr Primes, divisors, and congruences
- 09 Apr Binomial coefficients
- 08 Apr Using identities
- 07 Apr Cubic polynomials
- 07 Apr Quadratic polynomials
- 07 Apr Induction
- 03 Apr Inequalities
- 24 Mar System of equations
- 20 Mar Functional equations
- 18 Mar Integer divisibility
- 17 Mar Lagrange interpolation
- 17 Mar Crossing the $x$-axis
- 08 Mar Roots of unity
- 07 Mar Size of the roots
- 25 Feb Generating functions
- 24 Feb Counting in two different ways
- 23 Feb Counting the complement
- 22 Feb Counting via bijections
- 21 Feb Counting
- 20 Feb Grouping in pairs
- 20 Feb Arrange in order
- 19 Feb Extremal principle
- 18 Feb Pigeonhole principle
- 17 Feb Invariance principle
- 16 Feb Inclusion-exclusion principle
- 15 Feb Induction
- 14 Feb Auxiliary configuration
- 17 Jul Rational and irrational numbers
- 05 Jul Arithmetic progressions
- 26 Jun IOQM 2023
- 23 Jun More on polynomials
- 22 Jun RMO 2023 Questions, Hints, Walkthroughs, Discussions, Solutions
- 22 Jun Binomial theorem
- 19 Jun Growth of polynomials
- 18 Jun Telescoping
- 18 Jun Finite differences
- 18 Jun Differentiation and multiple roots
- 18 Jun Viete's relations
- 18 Jun Quartics
- 17 Jun Cubic polynomials
- 16 Jun Quadratic polynomials
- 15 Jun Polynomials
- 14 Jun Invariance principle
- 13 Jun $a^3 + b^3 + c^3 - 3abc$
- 12 Jun Warm Up (Algebra)
- 17 May Coloring proofs
- 15 May Warm Up (Combinatorics)