binomial theorem

E4686

The binomial theorem is a fundamental algebraic formula that provides a systematic way to expand powers of binomial expressions, playing a key role in combinatorics and mathematical analysis.

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Statements (47)

Predicate Object
instanceOf mathematical theorem
appliesTo (a + b)^n
canBeProvedBy Pascal's identity
combinatorial arguments
mathematical induction
category theorems in algebra
theorems in combinatorics
defines \binom{α}{k} = α(α-1)…(α-k+1)/k! for generalized exponents
describes expansion of powers of a binomial
field algebra
combinatorics
mathematical analysis
forComplexExponent (1 + x)^α = Σ_{k=0}^∞ \binom{α}{k} x^k for |x| < 1 and α ∈ ℂ
forRealExponent (1 + x)^α = Σ_{k=0}^∞ \binom{α}{k} x^k for |x| < 1
generalizedBy multinomial theorem
hasGeneralization generalized binomial theorem
surface form: Newton's generalized binomial theorem

generalized binomial theorem
hasGeneralTerm C(n,k) a^{n-k} b^k
hasHistoricalAttribution Isaac Newton
hasNumberOfTerms n + 1
hasSpecialCase (a + b)^2 = a^2 + 2ab + b^2
(a + b)^3 = a^3 + 3a^2b + 3ab^2 + b^3
(a + b)^4 = a^4 + 4a^3b + 6a^2b^2 + 4ab^3 + b^4
implies entries of Pascal's triangle are binomial coefficients
impliesIdentity Σ_{k=0}^n (-1)^k C(n,k) = 0 for n > 0
Σ_{k=0}^n C(n,k) = 2^n
Σ_{k=0}^n k C(n,k) = n 2^{n-1}
Σ_{k=0}^n k^2 C(n,k) = n(n+1)2^{n-2}
isSpecialCaseOf multinomial theorem
knownSince at least the 17th century in its general form
relatedConcept Pascal's identity
surface form: Pascal's rule

binomial coefficient identity
relatesTo Pascal's triangle
requires commutativity of addition for a and b in its usual form
n to be a nonnegative integer in its classical form
states (a + b)^n = Σ_{k=0}^n C(n,k) a^{n-k} b^k
symbolicallyUses C(n,k)
\binom{n}{k}
usedIn Taylor series computations
algebraic manipulation of polynomials
analysis of algorithms
binomial distribution
combinatorial counting problems
finite difference methods
probability theory
series expansions
uses binomial coefficients

Referenced by (2)

Full triples — surface form annotated when it differs from this entity's canonical label.

Isaac Newton knownFor binomial theorem
Pascal's triangle relatedTo binomial theorem