- j ({{MathWorld | urlname=j | title=j}}): J
- j-Conductor ({{MathWorld | urlname=j-Conductor | title=j-Conductor}}): J-conductor
- j-Function ({{MathWorld | urlname=j-Function | title=j-Function}}): J-function
- j-Invariant ({{MathWorld | urlname=j-Invariant | title=j-Invariant}}): J-invariant
- Jack Polynomial ({{MathWorld | urlname=JackPolynomial | title=Jack Polynomial}}): Jack polynomial
- Jackknife ({{MathWorld | urlname=Jackknife | title=Jackknife}}): Jackknife
- Jackson's Difference Fan ({{MathWorld | urlname=JacksonsDifferenceFan | title=Jackson's Difference Fan}}): Jackson's difference fan
- Jackson's Identity ({{MathWorld | urlname=JacksonsIdentity | title=Jackson's Identity}}): Jackson's identity
- Jackson's Theorem ({{MathWorld | urlname=JacksonsTheorem | title=Jackson's Theorem}}): Jackson's theorem
- Jackson-Slater Identity ({{MathWorld | urlname=Jackson-SlaterIdentity | title=Jackson-Slater Identity}}): Jackson-slater identity
- Jaco-Shalen-Johannson Torus Decomposition ({{MathWorld | urlname=Jaco-Shalen-JohannsonTorusDecomposition | title=Jaco-Shalen-Johannson Torus Decomposition}}): Jaco-shalen-johannson torus decomposition
- Jacobi Algorithm ({{MathWorld | urlname=JacobiAlgorithm | title=Jacobi Algorithm}}): Jacobi algorithm
- Jacobi Amplitude ({{MathWorld | urlname=JacobiAmplitude | title=Jacobi Amplitude}}): Jacobi amplitude
- Jacobi Differential Equation ({{MathWorld | urlname=JacobiDifferentialEquation | title=Jacobi Differential Equation}}): Jacobi differential equation
- Jacobi Elliptic Functions ({{MathWorld | urlname=JacobiEllipticFunctions | title=Jacobi Elliptic Functions}}): Jacobi elliptic functions
- Jacobi Function of the First Kind ({{MathWorld | urlname=JacobiFunctionoftheFirstKind | title=Jacobi Function of the First Kind}}): Jacobi function of the first kind
- Jacobi Function of the Second Kind ({{MathWorld | urlname=JacobiFunctionoftheSecondKind | title=Jacobi Function of the Second Kind}}): Jacobi function of the second kind
- Jacobi Identities ({{MathWorld | urlname=JacobiIdentities | title=Jacobi Identities}}): Jacobi identities
- Jacobi Matrix ({{MathWorld | urlname=JacobiMatrix | title=Jacobi Matrix}}): Jacobi matrix
- Jacobi Method ({{MathWorld | urlname=JacobiMethod | title=Jacobi Method}}): Jacobi method
- Jacobi Polynomial ({{MathWorld | urlname=JacobiPolynomial | title=Jacobi Polynomial}}): Jacobi polynomial
- Jacobi Quadrature ({{MathWorld | urlname=JacobiQuadrature | title=Jacobi Quadrature}}): Jacobi quadrature
- Jacobi Rotation Matrix ({{MathWorld | urlname=JacobiRotationMatrix | title=Jacobi Rotation Matrix}}): Jacobi rotation matrix
- Jacobi Symbol ({{MathWorld | urlname=JacobiSymbol | title=Jacobi Symbol}}): Jacobi symbol
- Jacobi Tensor ({{MathWorld | urlname=JacobiTensor | title=Jacobi Tensor}}): Jacobi tensor
- Jacobi Theta Functions ({{MathWorld | urlname=JacobiThetaFunctions | title=Jacobi Theta Functions}}): Jacobi theta functions
- Jacobi Transformation ({{MathWorld | urlname=JacobiTransformation | title=Jacobi Transformation}}): Jacobi transformation
- Jacobi Triple Product ({{MathWorld | urlname=JacobiTripleProduct | title=Jacobi Triple Product}}): Jacobi triple product
- Jacobi Zeta Function ({{MathWorld | urlname=JacobiZetaFunction | title=Jacobi Zeta Function}}): Jacobi zeta function
- Jacobi's Curvature Theorem ({{MathWorld | urlname=JacobisCurvatureTheorem | title=Jacobi's Curvature Theorem}}): Jacobi's curvature theorem
- Jacobi's Determinant Identity ({{MathWorld | urlname=JacobisDeterminantIdentity | title=Jacobi's Determinant Identity}}): Jacobi's determinant identity
- Jacobi's Imaginary Transformation ({{MathWorld | urlname=JacobisImaginaryTransformation | title=Jacobi's Imaginary Transformation}}): Jacobi's imaginary transformation
- Jacobi's Theorem ({{MathWorld | urlname=JacobisTheorem | title=Jacobi's Theorem}}): Jacobi's theorem
- Jacobi-Anger Expansion ({{MathWorld | urlname=Jacobi-AngerExpansion | title=Jacobi-Anger Expansion}}): Jacobi-anger expansion
- Jacobi-Gauss Quadrature ({{MathWorld | urlname=Jacobi-GaussQuadrature | title=Jacobi-Gauss Quadrature}}): Jacobi-gauss quadrature
- Jacobian ({{MathWorld | urlname=Jacobian | title=Jacobian}}): Jacobian
- Jacobian Conjecture ({{MathWorld | urlname=JacobianConjecture | title=Jacobian Conjecture}}): Jacobian conjecture
- Jacobian Curve ({{MathWorld | urlname=JacobianCurve | title=Jacobian Curve}}): Jacobian curve
- Jacobian Determinant ({{MathWorld | urlname=JacobianDeterminant | title=Jacobian Determinant}}): Jacobian determinant
- Jacobian Group ({{MathWorld | urlname=JacobianGroup | title=Jacobian Group}}): Jacobian group
- Jacobian Matrix ({{MathWorld | urlname=JacobianMatrix | title=Jacobian Matrix}}): Jacobian matrix
- JacobiCD ({{MathWorld | urlname=JacobiCD | title=JacobiCD}}): Jacobicd
- JacobiCN ({{MathWorld | urlname=JacobiCN | title=JacobiCN}}): Jacobicn
- JacobiCS ({{MathWorld | urlname=JacobiCS | title=JacobiCS}}): Jacobics
- JacobiDC ({{MathWorld | urlname=JacobiDC | title=JacobiDC}}): Jacobidc
- JacobiDN ({{MathWorld | urlname=JacobiDN | title=JacobiDN}}): Jacobidn
- JacobiDS ({{MathWorld | urlname=JacobiDS | title=JacobiDS}}): Jacobids
- JacobiNC ({{MathWorld | urlname=JacobiNC | title=JacobiNC}}): Jacobinc
- JacobiND ({{MathWorld | urlname=JacobiND | title=JacobiND}}): Jacobind
- JacobiNS ({{MathWorld | urlname=JacobiNS | title=JacobiNS}}): Jacobins
- JacobiP ({{MathWorld | urlname=JacobiP | title=JacobiP}}): Jacobip
- JacobiSC ({{MathWorld | urlname=JacobiSC | title=JacobiSC}}): Jacobisc
- JacobiSD ({{MathWorld | urlname=JacobiSD | title=JacobiSD}}): Jacobisd
- JacobiSN ({{MathWorld | urlname=JacobiSN | title=JacobiSN}}): Jacobisn
- JacobiZeta ({{MathWorld | urlname=JacobiZeta | title=JacobiZeta}}): Jacobizeta
- Jacobson Canonical Form ({{MathWorld | urlname=JacobsonCanonicalForm | title=Jacobson Canonical Form}}): Jacobson canonical form
- Jacobson Radical ({{MathWorld | urlname=JacobsonRadical | title=Jacobson Radical}}): Jacobson radical
- Jacobsthal Number ({{MathWorld | urlname=JacobsthalNumber | title=Jacobsthal Number}}): Jacobsthal number
- Jacobsthal Polynomial ({{MathWorld | urlname=JacobsthalPolynomial | title=Jacobsthal Polynomial}}): Jacobsthal polynomial
- Jacobsthal-Lucas Number ({{MathWorld | urlname=Jacobsthal-LucasNumber | title=Jacobsthal-Lucas Number}}): Jacobsthal-lucas number
- Jacobsthal-Lucas Polynomial ({{MathWorld | urlname=Jacobsthal-LucasPolynomial | title=Jacobsthal-Lucas Polynomial}}): Jacobsthal-lucas polynomial
- Jagged Number ({{MathWorld | urlname=JaggedNumber | title=Jagged Number}}): Jagged number
- Janko Groups ({{MathWorld | urlname=JankoGroups | title=Janko Groups}}): Janko groups
- Japanese Chess ({{MathWorld | urlname=JapaneseChess | title=Japanese Chess}}): Japanese chess
- Japanese Temple Problem ({{MathWorld | urlname=JapaneseTempleProblem | title=Japanese Temple Problem}}): Japanese temple problem
- Japanese Theorem ({{MathWorld | urlname=JapaneseTheorem | title=Japanese Theorem}}): Japanese theorem
- Japanese Triangulation Theorem ({{MathWorld | urlname=JapaneseTriangulationTheorem | title=Japanese Triangulation Theorem}}): Japanese triangulation theorem
- Jarnick's Inequality ({{MathWorld | urlname=JarnicksInequality | title=Jarnick's Inequality}}): Jarnick's inequality
- Jastrow Illusion ({{MathWorld | urlname=JastrowIllusion | title=Jastrow Illusion}}): Jastrow illusion
- Jeep Problem ({{MathWorld | urlname=JeepProblem | title=Jeep Problem}}): Jeep problem
- Jenkins' Theorem ({{MathWorld | urlname=JenkinsTheorem | title=Jenkins' Theorem}}): Jenkins' theorem
- Jenkins-Traub Method ({{MathWorld | urlname=Jenkins-TraubMethod | title=Jenkins-Traub Method}}): Jenkins-traub method
- Jensen Disk ({{MathWorld | urlname=JensenDisk | title=Jensen Disk}}): Jensen disk
- Jensen Polynomial ({{MathWorld | urlname=JensenPolynomial | title=Jensen Polynomial}}): Jensen polynomial
- Jensen's Formula ({{MathWorld | urlname=JensensFormula | title=Jensen's Formula}}): Jensen's formula
- Jensen's Inequality ({{MathWorld | urlname=JensensInequality | title=Jensen's Inequality}}): Jensen's inequality
- Jensen's Theorem ({{MathWorld | urlname=JensensTheorem | title=Jensen's Theorem}}): Jensen's theorem
- Jerabek Antipode ({{MathWorld | urlname=JerabekAntipode | title=Jerabek Antipode}}): Jerabek antipode
- Jerabek Center ({{MathWorld | urlname=JerabekCenter | title=Jerabek Center}}): Jerabek center
- Jerabek Hyperbola ({{MathWorld | urlname=JerabekHyperbola | title=Jerabek Hyperbola}}): Jerabek hyperbola
- Jerk ({{MathWorld | urlname=Jerk | title=Jerk}}): Jerk
- Jessen's Orthogonal Icosahedron ({{MathWorld | urlname=JessensOrthogonalIcosahedron | title=Jessen's Orthogonal Icosahedron}}): Jessen's orthogonal icosahedron
- Jet Bundle ({{MathWorld | urlname=JetBundle | title=Jet Bundle}}): Jet bundle
- Jiang Zemin's Problem ({{MathWorld | urlname=JiangZeminsProblem | title=Jiang Zemin's Problem}}): Jiang zemin's problem
- Jinc Function ({{MathWorld | urlname=JincFunction | title=Jinc Function}}): Jinc function
- Jitter ({{MathWorld | urlname=Jitter | title=Jitter}}): Jitter
- Joachimsthal's Circle ({{MathWorld | urlname=JoachimsthalsCircle | title=Joachimsthal's Circle}}): Joachimsthal's circle
- Joachimsthal's Equation ({{MathWorld | urlname=JoachimsthalsEquation | title=Joachimsthal's Equation}}): Joachimsthal's equation
- Johnson Association Scheme ({{MathWorld | urlname=JohnsonAssociationScheme | title=Johnson Association Scheme}}): Johnson association scheme
- Johnson Bound ({{MathWorld | urlname=JohnsonBound | title=Johnson Bound}}): Johnson bound
- Johnson Circles ({{MathWorld | urlname=JohnsonCircles | title=Johnson Circles}}): Johnson circles
- Johnson Circumconic ({{MathWorld | urlname=JohnsonCircumconic | title=Johnson Circumconic}}): Johnson circumconic
- Johnson Graph ({{MathWorld | urlname=JohnsonGraph | title=Johnson Graph}}): Johnson graph
- Johnson Midpoint ({{MathWorld | urlname=JohnsonMidpoint | title=Johnson Midpoint}}): Johnson midpoint
- Johnson Scheme ({{MathWorld | urlname=JohnsonScheme | title=Johnson Scheme}}): Johnson scheme
- Johnson Solid ({{MathWorld | urlname=JohnsonSolid | title=Johnson Solid}}): Johnson solid
- Johnson Triangle ({{MathWorld | urlname=JohnsonTriangle | title=Johnson Triangle}}): Johnson triangle
- Johnson Triangle Circumcircle ({{MathWorld | urlname=JohnsonTriangleCircumcircle | title=Johnson Triangle Circumcircle}}): Johnson triangle circumcircle
- Johnson's Equation ({{MathWorld | urlname=JohnsonsEquation | title=Johnson's Equation}}): Johnson's equation
- Johnson's Theorem ({{MathWorld | urlname=JohnsonsTheorem | title=Johnson's Theorem}}): Johnson's theorem
- Johnson-Yff Circles ({{MathWorld | urlname=Johnson-YffCircles | title=Johnson-Yff Circles}}): Johnson-yff circles
- Join ({{MathWorld | urlname=Join | title=Join}}): Join
- Join-Embedding ({{MathWorld | urlname=Join-Embedding | title=Join-Embedding}}): Join-embedding
- Join-Endomorphism ({{MathWorld | urlname=Join-Endomorphism | title=Join-Endomorphism}}): Join-endomorphism
- Join-Homomorphism ({{MathWorld | urlname=Join-Homomorphism | title=Join-Homomorphism}}): Join-homomorphism
- Join-Isomorphism ({{MathWorld | urlname=Join-Isomorphism | title=Join-Isomorphism}}): Join-isomorphism
- Joint Denial ({{MathWorld | urlname=JointDenial | title=Joint Denial}}): Joint denial
- Joint Distribution Function ({{MathWorld | urlname=JointDistributionFunction | title=Joint Distribution Function}}): Joint distribution function
- Joint Probability Density Function ({{MathWorld | urlname=JointProbabilityDensityFunction | title=Joint Probability Density Function}}): Joint probability density function
- Joint Theorem ({{MathWorld | urlname=JointTheorem | title=Joint Theorem}}): Joint theorem
- Joke Number ({{MathWorld | urlname=JokeNumber | title=Joke Number}}): Joke number
- Jonah Formula ({{MathWorld | urlname=JonahFormula | title=Jonah Formula}}): Jonah formula
- Joncquière's Relation ({{MathWorld | urlname=JoncquieresRelation | title=Joncquière's Relation}}): Joncquière's relation
- Jones Polynomial ({{MathWorld | urlname=JonesPolynomial | title=Jones Polynomial}}): Jones polynomial
- Jonquière's Function ({{MathWorld | urlname=JonquieresFunction | title=Jonquière's Function}}): Jonquière's function
- Jonquière's Relation ({{MathWorld | urlname=JonquieresRelation | title=Jonquière's Relation}}): Jonquière's relation
- Jonquière's Theorem ({{MathWorld | urlname=JonquieresTheorem | title=Jonquière's Theorem}}): Jonquière's theorem
- Jonquière's Transformation ({{MathWorld | urlname=JonquieresTransformation | title=Jonquière's Transformation}}): Jonquière's transformation
- Jordan Algebra ({{MathWorld | urlname=JordanAlgebra | title=Jordan Algebra}}): Jordan algebra
- Jordan Basis ({{MathWorld | urlname=JordanBasis | title=Jordan Basis}}): Jordan basis
- Jordan Block ({{MathWorld | urlname=JordanBlock | title=Jordan Block}}): Jordan block
- Jordan Canonical Form ({{MathWorld | urlname=JordanCanonicalForm | title=Jordan Canonical Form}}): Jordan canonical form
- Jordan Curve ({{MathWorld | urlname=JordanCurve | title=Jordan Curve}}): Jordan curve
- Jordan Curve Theorem ({{MathWorld | urlname=JordanCurveTheorem | title=Jordan Curve Theorem}}): Jordan curve theorem
- Jordan Decomposition Theorem ({{MathWorld | urlname=JordanDecompositionTheorem | title=Jordan Decomposition Theorem}}): Jordan decomposition theorem
- Jordan Identity ({{MathWorld | urlname=JordanIdentity | title=Jordan Identity}}): Jordan identity
- Jordan Matrix Decomposition ({{MathWorld | urlname=JordanMatrixDecomposition | title=Jordan Matrix Decomposition}}): Jordan matrix decomposition
- Jordan Measure ({{MathWorld | urlname=JordanMeasure | title=Jordan Measure}}): Jordan measure
- Jordan Measure Decomposition ({{MathWorld | urlname=JordanMeasureDecomposition | title=Jordan Measure Decomposition}}): Jordan measure decomposition
- Jordan Polygon ({{MathWorld | urlname=JordanPolygon | title=Jordan Polygon}}): Jordan polygon
- Jordan Product ({{MathWorld | urlname=JordanProduct | title=Jordan Product}}): Jordan product
- Jordan's Inequality ({{MathWorld | urlname=JordansInequality | title=Jordan's Inequality}}): Jordan's inequality
- Jordan's Lemma ({{MathWorld | urlname=JordansLemma | title=Jordan's Lemma}}): Jordan's lemma
- Jordan's Symmetric Group Theorem ({{MathWorld | urlname=JordansSymmetricGroupTheorem | title=Jordan's Symmetric Group Theorem}}): Jordan's symmetric group theorem
- Jordan-Hölder Theorem ({{MathWorld | urlname=Jordan-HoelderTheorem | title=Jordan-Hölder Theorem}}): Jordan-Hölder theorem
- Joseph Ideal ({{MathWorld | urlname=JosephIdeal | title=Joseph Ideal}}): Joseph ideal
- Josephus Problem ({{MathWorld | urlname=JosephusProblem | title=Josephus Problem}}): Josephus problem
- Joyce Sequence ({{MathWorld | urlname=JoyceSequence | title=Joyce Sequence}}): Joyce sequence
- Jug ({{MathWorld | urlname=Jug | title=Jug}}): Jug
- Jugendtraum ({{MathWorld | urlname=Jugendtraum | title=Jugendtraum}}): Jugendtraum
- Juggler Sequence ({{MathWorld | urlname=JugglerSequence | title=Juggler Sequence}}): Juggler sequence
- Juggling ({{MathWorld | urlname=Juggling | title=Juggling}}): Juggling
- Julia Fractal ({{MathWorld | urlname=JuliaFractal | title=Julia Fractal}}): Julia fractal
- Julia Set ({{MathWorld | urlname=JuliaSet | title=Julia Set}}): Julia set
- Julian Number ({{MathWorld | urlname=JulianNumber | title=Julian Number}}): Julian number
- Jump ({{MathWorld | urlname=Jump | title=Jump}}): Jump
- Jump Angle ({{MathWorld | urlname=JumpAngle | title=Jump Angle}}): Jump angle
- Jumping Champion ({{MathWorld | urlname=JumpingChampion | title=Jumping Champion}}): Jumping champion
- Jumping Octahedron ({{MathWorld | urlname=JumpingOctahedron | title=Jumping Octahedron}}): Jumping octahedron
- Jung's Theorem ({{MathWorld | urlname=JungsTheorem | title=Jung's Theorem}}): Jung's theorem
- Just If ({{MathWorld | urlname=JustIf | title=Just If}}): Just if
- Just One ({{MathWorld | urlname=JustOne | title=Just One}}): Just one
- Just Rigid ({{MathWorld | urlname=JustRigid | title=Just Rigid}}): Just rigid