User contributions
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- 10:57, 30 January 2021 (diff | hist) . . (+54) . . 1989 IMO Problems/Problem 4 (current)
- 10:56, 30 January 2021 (diff | hist) . . (+11) . . 1989 IMO Problems/Problem 3 (current)
- 10:55, 30 January 2021 (diff | hist) . . (+3,052) . . 1989 IMO Problems/Problem 3
- 10:50, 30 January 2021 (diff | hist) . . (+97) . . 1989 IMO Problems/Problem 2 (current)
- 10:47, 30 January 2021 (diff | hist) . . (+2,959) . . N 1989 IMO Problems (Created page with "Problems of the 1989 IMO. ==Day I== ===Problem 1=== Prove that in the set <math> \{1,2, \ldots, 1989\}</math> can be expressed as the disjoint union of subsets <math> A_i...")
- 10:39, 30 January 2021 (diff | hist) . . (+11) . . 1988 IMO Problems
- 10:38, 30 January 2021 (diff | hist) . . (+51) . . 1988 IMO Problems/Problem 5 (current)
- 10:38, 30 January 2021 (diff | hist) . . (+3,071) . . 1988 IMO Problems/Problem 5
- 10:36, 30 January 2021 (diff | hist) . . (+79) . . 1988 IMO Problems/Problem 4 (current)
- 10:35, 30 January 2021 (diff | hist) . . (+6,188) . . 1988 IMO Problems/Problem 3 (current)
- 10:32, 30 January 2021 (diff | hist) . . (+46) . . 1988 IMO Problems/Problem 2 (current)
- 10:32, 30 January 2021 (diff | hist) . . (+110) . . 1988 IMO Problems/Problem 1 (current)
- 10:29, 30 January 2021 (diff | hist) . . (+3,113) . . 1988 IMO Problems
- 10:12, 30 January 2021 (diff | hist) . . (-451) . . 1987 IMO Problems
- 10:12, 30 January 2021 (diff | hist) . . (0) . . 1986 IMO Problems/Problem 6 (current)
- 10:09, 30 January 2021 (diff | hist) . . (+5,094) . . N 1986 IMO Problems/Problem 6 (Created page with "==Problem== Given a finite set of points in the plane, each with integer coordinates, is it always possible to color the points red or white so that for any straight line <mat...")
- 10:06, 30 January 2021 (diff | hist) . . (+3,891) . . 1986 IMO Problems/Problem 5
- 10:02, 30 January 2021 (diff | hist) . . (+1,608) . . N 1986 IMO Problems/Problem 4 (Created page with "==Problem== Let <math>A,B</math> be adjacent vertices of a regular <math>n</math>-gon (<math>n\ge5</math>) with center <math>O</math>. A triangle <math>XYZ</math>, which is co...") (current)
- 10:01, 30 January 2021 (diff | hist) . . (+1,323) . . N 1986 IMO Problems/Problem 3 (Created page with "==Problem== To each vertex of a regular pentagon an integer is assigned, so that the sum of all five numbers is positive. If three consecutive vertices are assigned the number...")
- 23:04, 29 January 2021 (diff | hist) . . (+54) . . 1986 IMO Problems/Problem 2
- 23:04, 29 January 2021 (diff | hist) . . (-768) . . 1986 IMO Problems/Problem 1
- 23:04, 29 January 2021 (diff | hist) . . (+478) . . 1986 IMO Problems (current)
- 23:02, 29 January 2021 (diff | hist) . . (+10) . . 1985 IMO Problems/Problem 6 (→Solution 3)
- 23:01, 29 January 2021 (diff | hist) . . (+9,032) . . 1985 IMO Problems/Problem 6
- 22:56, 29 January 2021 (diff | hist) . . (+54) . . 1985 IMO Problems/Problem 5
- 22:56, 29 January 2021 (diff | hist) . . (+54) . . 1985 IMO Problems/Problem 4 (current)
- 22:54, 29 January 2021 (diff | hist) . . (+149) . . 1985 IMO Problems
- 22:53, 29 January 2021 (diff | hist) . . (+3,693) . . N 1984 IMO Problems/Problem 6 (Created page with "==Problem== Let <math>a,b,c,d</math> be odd integers such that <math>0<a<b<c<d</math> and <math>ad=bc</math>. Prove that if <math>a+d=2^k</math> and <math>b+c=2^m</math> for s...") (current)
- 22:50, 29 January 2021 (diff | hist) . . (+1,348) . . N 1984 IMO Problems/Problem 5 (Created page with "==Problem== Let <math> d</math> be the sum of the lengths of all the diagonals of a plane convex polygon with <math> n</math> vertices (where <math> n>3</math>). Let <math> p<...") (current)
- 22:49, 29 January 2021 (diff | hist) . . (+38) . . 1984 IMO Problems/Problem 4 (current)
- 22:49, 29 January 2021 (diff | hist) . . (0) . . 1984 IMO Problems/Problem 3 (current)
- 22:48, 29 January 2021 (diff | hist) . . (+2,105) . . N 1984 IMO Problems/Problem 3 (Created page with "==Problem== Given points <math>O</math> and <math>A</math> in the plane. Every point in the plane is colored with one of a finite number of colors. Given a point <math>X</math...")
- 22:47, 29 January 2021 (diff | hist) . . (+1,046) . . N 1984 IMO Problems/Problem 2 (Created page with "==Problem== Find one pair of positive integers <math>a,b</math> such that <math>ab(a+b)</math> is not divisible by <math>7</math>, but <math>(a+b)^7-a^7-b^7</math> is divisibl...")
- 22:45, 29 January 2021 (diff | hist) . . (+68) . . 1984 IMO Problems/Problem 1
- 22:45, 29 January 2021 (diff | hist) . . (+2,467) . . N 1984 IMO Problems (Created page with "Problems of the 1984 IMO. ==Day I== ===Problem 1=== Prove that <math>0\le yz+zx+xy-2xyz\le{7\over27}</math>, where <math>x,y</math> and <math>z</math> are non-negative re...") (current)
- 22:41, 29 January 2021 (diff | hist) . . (+65) . . 1983 IMO Problems/Problem 6
- 22:40, 29 January 2021 (diff | hist) . . (+54) . . 1983 IMO Problems/Problem 5 (current)
- 22:40, 29 January 2021 (diff | hist) . . (0) . . 1983 IMO Problems/Problem 4 (current)
- 22:39, 29 January 2021 (diff | hist) . . (+1,678) . . 1983 IMO Problems/Problem 4
- 22:37, 29 January 2021 (diff | hist) . . (+3,372) . . 1983 IMO Problems/Problem 3 (current)
- 22:35, 29 January 2021 (diff | hist) . . (+6,572) . . 1983 IMO Problems/Problem 2 (current)
- 22:29, 29 January 2021 (diff | hist) . . (+878) . . N 1982 IMO Problems/Problem 6 (Created page with "==Problem== Let <math>S</math> be a square with sides length <math>100</math>. Let <math>L</math> be a path within <math>S</math> which does not meet itself and which is compo...")
- 22:27, 29 January 2021 (diff | hist) . . (0) . . 1982 IMO Problems/Problem 5
- 22:26, 29 January 2021 (diff | hist) . . (+3,095) . . N 1982 IMO Problems/Problem 5 (Created page with "==Problem== The diagonals <math>AC</math> and <math>CE</math> of the regular hexagon <math>ABCDEF</math> are divided by inner points <math>M</math> and <math>N</math> respecti...")
- 22:23, 29 January 2021 (diff | hist) . . (+2,646) . . N 1982 IMO Problems/Problem 3 (Created page with "==Problem== Consider infinite sequences <math>\{x_n\}</math> of positive reals such that <math>x_0=1</math> and <math>x_0\ge x_1\ge x_2\ge\ldots</math>. a) Prove that for eve...") (current)
- 22:19, 29 January 2021 (diff | hist) . . (+3,852) . . N 1982 IMO Problems/Problem 2 (Created page with "==Problem== A non-isosceles triangle <math>A_{1}A_{2}A_{3}</math> has sides <math>a_{1}</math>, <math>a_{2}</math>, <math>a_{3}</math> with the side <math>a_{i}</math> lying o...") (current)
- 22:17, 29 January 2021 (diff | hist) . . (0) . . 1982 IMO Problems/Problem 1 (current)
- 22:16, 29 January 2021 (diff | hist) . . (+4,340) . . N 1982 IMO Problems/Problem 1 (Created page with "==Problem== The function <math>f(n)</math> is defined on the positive integers and takes non-negative integer values. <math>f(2)=0,f(3)>0,f(9999)=3333</math> and for all <math...")
- 22:10, 29 January 2021 (diff | hist) . . (+1) . . 1982 IMO Problems (current)
- 22:09, 29 January 2021 (diff | hist) . . (+54) . . 1981 IMO Problems/Problem 5 (current)
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