Every idea

Ideas 601–750 of 7806.

Name	Kind	Subject
Truth table	Concept	Mathematical logic and foundations
Permutation	Concept	Combinatorics
Standard score	Definition	Statistics
Harmonic numbers grow like log n	Theorem	Number theory
Left inverse	Concept	Mathematical logic and foundations
Negation of an existential statement	Theorem	Mathematical logic and foundations
Poisson point process	Definition	Probability theory and stochastic processes
Group of units of a ring	Definition	Associative rings and algebras
Equality of complex numbers	Proposition	Functions of a complex variable
Phase plane	Concept	Ordinary differential equations
Maximal ideals are prime	Corollary	Commutative algebra
Submodule	Concept	Associative rings and algebras
Inverse trigonometric functions	Concept	Special functions
Jacobian of spherical coordinates	Proposition	Real functions
Number of derangements	Concept	Combinatorics
Set difference	Concept	Mathematical logic and foundations
Laplace transform	Definition	Integral transforms, operational calculus
Subgroups of solvable groups are solvable	Proposition	Group theory and generalizations
Asymptotic stability	Definition	Ordinary differential equations
Composition of linear maps	Definition	Linear and multilinear algebra; matrix theory
Isolated singularity	Concept	Functions of a complex variable
Perfect matching	Definition	Combinatorics
Circle	Concept	Geometry
Right coset	Definition	Group theory and generalizations
Law of cosines	Theorem	Geometry
Carmichael number	Concept	Number theory
Lucas–Lehmer test	Theorem	Number theory
Symmetric relation	Concept	Mathematical logic and foundations
Tree	Concept	Combinatorics
Trail	Definition	Combinatorics
Gamma distribution	Definition	Probability theory and stochastic processes
Nilpotent endomorphism	Concept	Linear and multilinear algebra; matrix theory
First fundamental theorem of calculus	Theorem	Real functions
Goldbach's conjecture	Conjecture	Number theory
Metric space	Definition	General topology
Order of a zero	Definition	Functions of a complex variable
LaSalle's invariance principle	Theorem	Ordinary differential equations
Coprime ideals	Concept	Commutative algebra
Surface integral	Concept	Real functions
Inclusion of a subspace is continuous	Proposition	General topology
Area of a triangle	Concept	Geometry
Repeating decimals are rational	Theorem	Number theory
De Moivre–Laplace theorem	Theorem	Probability theory and stochastic processes
Arctangent	Definition	Special functions
Radius of convergence	Definition	Functions of a complex variable
Pole	Concept	Functions of a complex variable
Closed subsets of compact sets are compact	Proposition	General topology
The integers are countable	Proposition	Mathematical logic and foundations
Noetherian ring	Concept	Commutative algebra
Flow of a vector field	Concept	Dynamical systems and ergodic theory
Autonomous system	Concept	Ordinary differential equations
Repeated roots and the derivative	Theorem	Commutative algebra
Scalar matrix	Concept	Linear and multilinear algebra; matrix theory
Tonelli's theorem	Theorem	Measure and integration
Existence of square roots of nonnegative reals	Theorem	Real functions
Closure in a metric space	Proposition	General topology
Diameter of a set	Definition	General topology
Hessian matrix	Concept	Real functions
Triple integral	Concept	Real functions
Uniqueness of splitting fields	Theorem	Field theory and polynomials
Comparison of a series and an integral	Proposition	Real functions
Row space	Concept	Linear and multilinear algebra; matrix theory
Partition of an interval	Definition	Real functions
Laplace expansion along a column	Theorem	Linear and multilinear algebra; matrix theory
Heine–Cantor theorem	Theorem	General topology
Solution formula for linear first-order equations	Theorem	Ordinary differential equations
Strictly convex function	Definition	Real functions
Reflection	Concept	Linear and multilinear algebra; matrix theory
Five colour theorem	Theorem	Combinatorics
Symmetric polynomial	Definition	Combinatorics
Integral of the exponential function	Proposition	Real functions
P-group	Definition	Group theory and generalizations
Identity matrix	Object	Linear and multilinear algebra; matrix theory
Z[x] is not a principal ideal domain	Counterexample	Commutative algebra
Fréchet derivative	Concept	Functional analysis
Operator norm	Concept	Operator theory
Basis of a topology	Definition	General topology
Midpoint	Definition	Geometry
Boolean algebra	Definition	Order, lattices, ordered algebraic structures
Mersenne prime	Definition	Number theory
Logical equivalence	Definition	Mathematical logic and foundations
Banach space	Concept	Functional analysis
Prime ideal	Definition	Commutative algebra
Uniform metric on bounded functions	Example	Functional analysis
Linear map of a matrix	Concept	Linear and multilinear algebra; matrix theory
Dimension of a direct product	Proposition	Linear and multilinear algebra; matrix theory
Grassmann's formula	Theorem	Linear and multilinear algebra; matrix theory
Affine combination	Definition	Geometry
Spectral theorem	Theorem	Operator theory
Multiplication of natural numbers	Concept	Mathematical logic and foundations
Classification of finite simple groups	Theorem	Group theory and generalizations
Real and imaginary parts	Concept	Functions of a complex variable
Regular curve	Definition	Differential geometry
Homogeneous system of linear equations	Definition	Linear and multilinear algebra; matrix theory
Branch cut	Definition	Functions of a complex variable
Convergence of a sequence in a metric space	Definition	General topology
Power series of the exponential function	Theorem	Special functions
The minimal polynomial divides every polynomial vanishing at the element	Proposition	Field theory and polynomials
Directional derivative	Concept	Real functions
Inflection point	Concept	Real functions
Solution of a linear recurrence	Concept	Difference and functional equations
Every spanning set contains a basis	Theorem	Linear and multilinear algebra; matrix theory
Fermat prime	Concept	Number theory
Cauchy criterion for series	Theorem	Sequences, series, summability
Dimension of the annihilator	Proposition	Linear and multilinear algebra; matrix theory
cosh^2 - sinh^2 = 1	Proposition	Special functions
P-group	Concept	Group theory and generalizations
Commutator of two elements	Definition	Group theory and generalizations
Units of the Gaussian integers	Proposition	Number theory
Number of invertible residues modulo n	Proposition	Number theory
Completion of a metric space	Concept	General topology
Disjunctive normal form	Definition	Mathematical logic and foundations
Graph homomorphism	Definition	Combinatorics
Continuous functions are Riemann integrable	Theorem	Real functions
Continuously differentiable function	Definition	Real functions
Tangent function	Definition	Special functions
Sum of divisors	Concept	Number theory
Rayleigh quotient	Concept	Linear and multilinear algebra; matrix theory
Existence of Laurent expansions on an annulus	Theorem	Functions of a complex variable
Converse of Wilson's theorem	Proposition	Number theory
Buffon's needle problem	Problem	Probability theory and stochastic processes
Simple continued fraction	Definition	Number theory
Decimal expansion	Definition	Number theory
Unique factorisation domain	Definition	Commutative algebra
Geometric multiplicity	Definition	Linear and multilinear algebra; matrix theory
Continuous image of a closed interval is a closed interval	Corollary	Real functions
Contour integral	Concept	Functions of a complex variable
Argument of a complex number	Concept	Functions of a complex variable
Finite set	Concept	Mathematical logic and foundations
Geometric formula for the dot product	Proposition	Geometry
Linear isometry	Definition	Linear and multilinear algebra; matrix theory
Abelian group	Definition	Group theory and generalizations
Congruence is compatible with multiplication	Proposition	Number theory
Maximal element	Concept	Order, lattices, ordered algebraic structures
Comparison of topologies	Concept	General topology
Formal power series	Definition	Commutative algebra
Limit of a product of sequences	Proposition	Sequences, series, summability
Cyclic groups of the same order are isomorphic	Theorem	Group theory and generalizations
Third isomorphism theorem for rings	Theorem	Associative rings and algebras
Associativity of matrix multiplication	Proposition	Linear and multilinear algebra; matrix theory
Tangent plane and normal vector of a surface	Concept	Differential geometry
Order of a pole	Concept	Functions of a complex variable
Kolmogorov's zero–one law	Theorem	Probability theory and stochastic processes
Correspondence between equivalence relations and partitions	Theorem	Mathematical logic and foundations
Symmetric bilinear form	Definition	Linear and multilinear algebra; matrix theory
Separable equation	Concept	Ordinary differential equations
Gaussian integer	Concept	Number theory
One-sided inverse of a square matrix is two-sided	Proposition	Linear and multilinear algebra; matrix theory
Simply connected domain	Definition	Algebraic topology
The reals have the cardinality of the continuum	Theorem	Mathematical logic and foundations