Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. Theorema Egregium : The Gaussian curvature of surfaces is preserved by local isometries.
Theorem of the Day (March 29, 2026) : Theorema Egregium
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/aVKxsrq
notes : buff.ly/GMAtTWJ
#mathematics #maths #math #theorem
#PSEUDOPOSTEGA #PARAPLICATELLA
allgraph.ro/advanced-sea...
#BOURBAKI #WITT #THEOREM
multi-search-tag-explorer.aepiot.ro/advanced-sea...
#PSEUDOPOSTEGA #PARAKEMPELLA
multi-search-tag-explorer.allgraph.ro/advanced-sea...
headlines-world.com
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. Euler’s Formula : For any real or complex value of θ, e^(iθ) = cos θ + i sin θ.
Theorem of the Day (March 28, 2026) : Euler’s Formula
Source : Theorem of the Day / Robin Whitty
pdf : www.theoremoftheday.org/GeometryAndT...
notes : www.theoremoftheday.org/Resources/Th...
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. Wallis’s Product : The value of τ/4 (τ = 2π) is given by the infinite product ∏_(k=1)^∞ (2k)^2 / ((2k − 1)(2k + 1)) = 2^2/(1.3). 4^2/(3.5). 6^2/(5.7) . . . .
Theorem of the Day (March 27, 2026) : Wallis’s Product
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/aWrmwXu
notes : buff.ly/80A3S1G
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. 1-Factorisation of Regular Graphs : There exists a constant, c, such that all simple d-regular graphs of even order, n, with cn ≤ d, have a 1-factorisation.
Theorem of the Day (March 26, 2026) : 1-Factorisation of Regular Graphs
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/ZdbcnNG
notes : buff.ly/Lz8ToDb
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. Bondy’s Subset Theorem : Let S be a set with n elements and suppose that n distinct subsets of S are chosen. Then there is a restriction to n − 1 elements of S under which these subsets remain distinct.
Theorem of the Day (March 25, 2026) : Bondy’s Subset Theorem
Source : Theorem of the Day / Robin Whitty
pdf : www.theoremoftheday.org/InformationT...
notes : www.theoremoftheday.org/Resources/Th...
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. The Girard–Newton Identities : For a fixed set S of variables, denote by e_k, 0 ≤ k ≤ |S |, the k-th elementary symmetric polynomial in the variables of S ; that is e_k = ∑_(X⊂S, |X|=k) ∏_(x∈X) x, with e_0 = 1. Denote by p_k the k-th power sum over S ; that is p_k = ∑_(x∈S) x^k. Then the following recurrence holds: ke_k = ∑_(i=1)^k (−1)^(i−1) p_i e_(k−i), for k ≥ 1.
Theorem of the Day (March 24, 2026) : The Girard–Newton Identities
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/LKaPQ4r
notes : buff.ly/aQ25glN
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem : The Change of Variables Theorem.
Theorem of the Day (March 23, 2026) : The Change of Variables Theorem
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/khUwmVj
notes : buff.ly/mkHciCz
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. The Handshaking Lemma : In any graph the sum of the vertex degrees is equal to twice the number of edges.
Theorem of the Day (March 22, 2026) : The Handshaking Lemma
Source : Theorem of the Day / Robin Whitty
pdf : www.theoremoftheday.org/Combinatoria...
notes : www.theoremoftheday.org/Resources/Th...
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem : Integration By Parts.
Theorem of the Day (March 21, 2026) : Integration By Parts
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/HRNCIC0
notes : buff.ly/d2I8Irg
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. The Fifteen Theorem : If a positive-definite quadratic form defined by a symmetric, integral matrix takes each of the values 1, 2, 3, 5, 6, 7, 10, 14, 15, then it takes all positive integer values.
Theorem of the Day (March 20, 2026) : The Fifteen Theorem
Source : Theorem of the Day / Robin Whitty
pdf : www.theoremoftheday.org/NumberTheory...
notes : www.theoremoftheday.org/Resources/Th...
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. The Basel Problem : 1 + 1 / 4 + 1 / 9 + . . . = ∑_(k=1)^∞ (1 / k^2) = τ^2 / 24.
Theorem of the Day (March 19, 2026) : The Basel Problem
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/UzSCvC7
notes : buff.ly/9Ualhkz
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. Euler’s Partition Identity : The number of partitions of a positive integer n into distinct parts is equal to the number of partitions of n into odd parts.
Theorem of the Day (March 18, 2026) : Euler’s Partition Identity
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/25basqG
notes : buff.ly/U0E98qn
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. Tunnell’s Theorem : Let n be a square-free positive integer and denote by S_n(a, b, c) the number of solutions in integers, x, y, z, of the equation ax^2 + by^2 + cz^2 = n. Then a necessary condition for n to be a congruent number is that S_n(2, 1, 8) = 2S_n(2, 1, 32) n odd and S_n(8, 2, 16) = 2S_n(8, 2, 64) n even . Moreover, if the Birch and Swinnerton-Dyer conjecture is true then this condition is also sufficient.
Theorem of the Day (March 17, 2026) : Tunnell’s Theorem
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/wdAdfGc
notes : buff.ly/gv8xew2
#mathematics #maths #math #theorem
The Math that explains why Bell Curves are everywhere [via @quantamagazine.bsky.social] 🧪🥼➗🔔
"when you combine many random actions, the result follows a reliable pattern."
www.quantamagazine.org/the-math-tha...
#statistics #normal #distribution #bell #curve #central #limit #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. The Three-Distance Theorem : Let α ∈ (0, 1) be irrational and let N be a positive integer. Then the set of lengths {kα | 0 ≤ k ≤ N}, measured around the unit-circumference circle, partitions the circle into N + 1 intervals, whose lengths take just two values, or three values of which one is the sum of the other two.
Theorem of the Day (March 16, 2026) : The Three-Distance Theorem
Source : Theorem of the Day / Robin Whitty
pdf : www.theoremoftheday.org/NumberTheory...
notes : www.theoremoftheday.org/Resources/Th...
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. Praeger’s Theorem on Bounded Movement : Let G be a permutation group acting without fixed points on a set Ω. Denote by m the maximum size of any subset Γ ⊆ Ω whose image under some group element is disjoint from Γ; and suppose that m is finite. Then Ω is a finite set; the number t of G orbits is at most 2m − 1; each orbit has length at most 3m; and |Ω| ≤ 3m + t − 1 ≤ 5m − 2.
Theorem of the Day (March 15, 2026) : Praeger’s Theorem on Bounded Movement
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/OjxKS72
notes : buff.ly/tL31ux6
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. Pick’s Theorem : Let P be a simple polygon (i.e. containing no holes or separate pieces) whose vertices lie on the points of a rectangular lattice. Suppose that I lattice points are located in the interior of P and B lattices points lie on the boundary of P. Then the area of P is given by K = I + B/2 − 1
Theorem of the Day (March 14, 2026) : Pick’s Theorem
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/IlPfcat
notes : buff.ly/R1AjXKZ
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. De Moivre’s Theorem : Let θ be an angle and n a positive integer. Then (cos θ + i sin θ)^n = cos nθ + i sin nθ.
Theorem of the Day (March 13, 2026) : De Moivre’s Theorem
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/ADn1ujE
notes : buff.ly/hKorjqZ
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. Countability of the Rationals : There is a one-to-one correspondence between the set of positive integers and the set of positive rational numbers.
Theorem of the Day (March 12, 2026) : Countability of the Rationals
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/e4IJiYa
notes : buff.ly/fqDjJbQ
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. Brahmagupta’s Formula : The area K of a cyclic quadrilateral with side lengths a, b, c, d and semiperimeter s = (a + b + c + d)/2 is given by K = √((s − a)(s − b)(s − c)(s − d)).
Theorem of the Day (March 11, 2026) : Brahmagupta’s Formula
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/SvBNXmR
notes : buff.ly/uITdf6I
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. The Riemann Rearrangement Theorem : If ∑_(k=0)^∞ a_k is a series which is conditionally convergent, and c is any real number, then the terms of the series may be rearranged to give convergence to c, i.e. there is a permutation π of the nonnegative integers such that ∑ a_(π(k)) = c.
Theorem of the Day (March 10, 2026) : The Riemann Rearrangement Theorem
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/fnN4vpA
notes : buff.ly/0G72KAO
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. The Fundamental Theorem of Arithmetic : Every integer greater than one can be expressed uniquely (up to order) as a product of powers of primes.
Theorem of the Day (March 9, 2026) : The Fundamental Theorem of Arithmetic
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/HyCAVdL
notes : buff.ly/hJxskAz
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. Singmaster’s Binomial Multiplicity Bound : For integer k > 1, let N(k) denote the multiplicity of k as a binomial coefficient; i.e. N(k) =∣{(n, r) ∈ Z^2 : k = "n choose r"}∣. Then N(k) = O(log k).
Theorem of the Day (March 8, 2026) : Singmaster’s Binomial Multiplicity Bound
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/68VtkiC
notes : buff.ly/JA1MRg1
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem : Viète’s Formula.
Theorem of the Day (March 7, 2026) : Viète’s Formula
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/U64te0w
notes : buff.ly/36wtRF4
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. Kepler’s Conjecture : Any packing of three-dimensional Euclidean space with equal-radius spheres has density bounded by τ √2/12 ≈ 0.74.
Theorem of the Day (March 6, 2026) : Kepler’s Conjecture
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/3855EnW
notes : buff.ly/nclvnzQ
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. Kasteleyn’s Theorem : Suppose that G is a planar graph drawn in the plane. Then 1. we can orient the edges so that every face has an odd number of clockwise-oriented edges, and 2. if A(G) is the signed adjacency matrix of such an orientation of G then number of perfect matchings of G = √det(A(G)).
Theorem of the Day (March 5, 2026) : Kasteleyn’s Theorem
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/IbGFiRS
notes : buff.ly/jt8wX9k
#mathematics #maths #math #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. The Bruck-Ryser-Chowla Theorem : If a projective plane of order n exists, with n ≡ 1 or 2 (mod 4) then n = x^2 + y^2 for some integers x and y.
Theorem of the Day (March 4, 2026) : The Bruck-Ryser-Chowla Theorem
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/kcz0V6o
notes : buff.ly/NrrOUxL
#mathematics #maths #math #theorem
The Six Circles Theorem illustrated janmr.com/posts/six-ci... #math #visualization #geometry #theorem
Comprehensive presentation of the "Theorem of the Day", starting with a statement of this theorem. The Erdos–Ko–Rado Theorem : Let n and k be positive integers, with n ≥ 2k. In a set of cardinality n, a family of distinct subsets of cardinality k, no two of which are disjoint, can have at most "(n-1) choose (k-1)" members.
Theorem of the Day (March 3, 2026) : The Erdos–Ko–Rado Theorem
Source : Theorem of the Day / Robin Whitty
pdf : buff.ly/JWVMGyl
notes : buff.ly/CfDI0yp
#mathematics #maths #math #theorem
