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WOLFRAM

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Solve

Solve[expr,vars]

attempts to solve the systemexpr of equations or inequalities for the variablesvars.

Solve[expr,vars,dom]

solves over the domaindom. Common choices ofdom areReals,Integers, andComplexes.

Details and Options
Details and OptionsDetails and Options
Examples  
Basic Examples  
Scope  
Basic Uses  
Complex Equations in One Variable  
Systems of Complex Equations in Several Variables  
Show MoreShow More
Real Equations in One Variable  
Systems of Real Equations and Inequalities in Several Variables  
Diophantine Equations  
Modular Equations  
Equations over Finite Fields  
Systems with Mixed Variable Domains  
Systems with Geometric Region Constraints  
Generalizations & Extensions  
Options  
Assumptions  
Cubics  
GeneratedParameters  
Show MoreShow More
InverseFunctions  
MaxExtraConditions  
MaxRoots  
Method  
Modulus  
Quartics  
VerifySolutions  
WorkingPrecision  
Applications  
Properties & Relations  
Possible Issues  
See Also
Tech Notes
Related Guides
History
Cite this Page

Solve

Solve[expr,vars]

attempts to solve the systemexpr of equations or inequalities for the variablesvars.

Solve[expr,vars,dom]

solves over the domaindom. Common choices ofdom areReals,Integers, andComplexes.

Details and Options

  • The systemexpr can be any logical combination of:
  • lhs==rhsequations
    lhs!=rhsinequations
    lhs>rhs orlhs>=rhsinequalities
    exprdomdomain specifications
    {x,y,}regregion specification
    ForAll[x,cond,expr]universal quantifiers
    Exists[x,cond,expr]existential quantifiers
  • Solve[{expr1,expr2,},vars] is equivalent toSolve[expr1&&expr2&&,vars].
  • A single variable or a list of variables can be specified.
  • Solve gives solutions in terms of rules of the form:
  • {}no solutions
    {{x->solx,y->soly,},}several solutions
    {{}}solution set is full dimensional
  • When a single variable is specified and a particular root of an equation has multiplicity greater than one,Solve gives several copies of the corresponding solution.
  • Solve[expr,vars] assumes by default that quantities appearing algebraically in inequalities are real, while all other quantities are complex.
  • Solve[expr,vars,dom] restricts all variables and parameters to belong to the domaindom.
  • Ifdom isReals, or a subset such asIntegers orRationals, then all constants and function values are also restricted to be real.
  • Solve[expr&&varsReals,vars,Complexes] solves for real values of variables, but function values are allowed to be complex.
  • Solve[expr,vars,Integers] solves Diophantine equations over the integers.
  • Solve[,xreg,Reals] constrainsx to be in the regionreg. The different coordinates forx can be referred to usingIndexed[x,i].
  • Algebraic variables inexpr free ofvars and of each other are treated as independent parameters.
  • Solve deals primarily with linear and polynomial equations.
  • Whenexpr involves only polynomial equations and inequalities over real or complex domains, thenSolve can always in principle solve directly forvars.
  • Whenexpr involves transcendental conditions or integer domains,Solve will often introduce additional parameters in its results.
  • Solve can give explicit representations for solutions to all linear equations and inequalities over the integers and can solve a large fraction of Diophantine equations described in the literature.
  • Whenexpr involves only polynomial conditions over real or complex domains,Solve[expr,vars] will always be able to eliminate quantifiers.
  • Solve gives generic solutions only. Solutions that are valid only when continuous parameters satisfy equations are removed. Other solutions that are only conditionally valid are expressed asConditionalExpression objects.
  • Conditions included inConditionalExpression solutions may involve inequalities,Element statements, equations and inequations on non-continuous parameters, and equations with full-dimensional solutions. Inequations andNotElement conditions on continuous parameters and variables are dropped.
  • Solve may use non-equivalent transformations to find solutions of transcendental equations and hence it may not find some solutions and may not establish exact conditions on the validity of the solutions found. If this happens, an error message is issued.
  • Solve uses special efficient techniques for handling sparse systems of linear equations with approximate numerical coefficients.
  • The following options can be given:
  • Assumptions$Assumptionsassumptions on parameters
    CubicsAutomaticwhether to use explicit radicals to solve all cubics
    GeneratedParametersChow to name parameters that are generated
    InverseFunctionsAutomaticwhether to use symbolic inverse functions
    MaxExtraConditions0how many extra equational conditions on continuous parameters to allow
    MaxRootsInfinitymaximum number of roots returned
    MethodAutomaticwhat method should be used
    Modulus0modulus to assume for integers
    QuarticsAutomaticwhether to use explicit radicals to solve all quartics
    VerifySolutionsAutomaticwhether to verify solutions obtained using non-equivalent transformations
    WorkingPrecisionInfinityprecision to be used in computations
  • WithMaxExtraConditions->Automatic, only solutions that require the minimal number of equational conditions on continuous parameters are included.
  • WithMaxExtraConditions->All, solutions that require arbitrary conditions on parameters are given and all conditions are included.
  • WithMaxExtraConditions->k, only solutions that require at mostk equational conditions on continuous parameters are included.
  • WithMethod->Reduce,Solve uses only equivalent transformations and finds all solutions.
  • Solve[eqns,,Modulus->m] solves equations over the integers modulom. WithModulus->Automatic,Solve will attempt to find the largest modulus for which the equations have solutions.

Examples

open allclose all

Basic Examples  (5)

Solve a quadratic equation:

Solve simultaneous equations in and:

Solve an equation over the reals:

Solve an equation over the positive integers:

Solve equations in a geometric region:

Scope  (85)

Basic Uses  (6)

Solutions are given as lists of replacements:

UseReplaceAll (/.) to replace by solutions:

Check that solutions satisfy the equations:

Solve uses{} to represent the empty solution or no solution:

Solve uses{{}} to represent the universal solution or all points satisfying the equations:

Find solutions over specified domains:

Solve equations with coefficients involving a symbolic parameter:

Plot the real parts of the solutions fory as a function of the parametera:

Solution of this equation over the reals requires conditions on the parameters:

Replacex by solutions and simplify the results:

UseNormal to remove the conditions:

Solution of this equation over the positive integers requires introduction of a new parameter:

List the first 10 solutions:

Complex Equations in One Variable  (15)

Polynomial equations solvable in radicals:

To use general formulas for solving cubic equations, setCubicsTrue:

By default,Solve usesRoot objects to represent solutions of general cubic equations with numeric coefficients:

General polynomial equations:

Polynomial equations with multiple roots:

Find five roots of a polynomial of a high degree:

Polynomial equations with symbolic coefficients:

Algebraic equations:

Transcendental equations:

Solve cannot find all solutions here:

Find three solutions:

Univariate elementary function equations over bounded regions:

Univariate holomorphic function equations over bounded regions:

HereSolve finds some solutions but is not able to prove there are no other solutions:

Equation with a purely imaginary period over a vertical stripe in the complex plane:

Find a specified number of roots of an unrestricted complex equation:

Symbolic functions:

Nonanalytic complex equations:

Systems of Complex Equations in Several Variables  (12)

Systems of linear equations:

Linear equations with symbolic coefficients:

Underdetermined systems of linear equations:

Linear equations with no solutions:

Systems of polynomial equations:

Find five out of a trillion roots of a polynomial system:

Polynomial equations with symbolic coefficients:

Algebraic equations:

Transcendental equations:

Find a specified number of solutions of transcendental equations:

Square analytic systems over bounded boxes:

Nonanalytic equations:

Real Equations in One Variable  (13)

Polynomial equations:

Polynomial equations with multiple roots:

Polynomial equations with symbolic coefficients:

Algebraic equations:

Piecewise equations:

Transcendental equations, solvable using inverse functions:

Transcendental equations, solvable using special function zeros:

Transcendental inequalities, solvable using special function zeros:

Exp-log equations:

High-degree sparse polynomial equations:

Algebraic equations involving high-degree radicals:

Equations involving non-rational real powers:

Equation with a double root:

Tame elementary function equations:

Elementary function equations in bounded intervals:

Holomorphic function equations in bounded intervals:

Periodic elementary function equations over the reals:

Systems of Real Equations and Inequalities in Several Variables  (10)

Linear systems:

Polynomial systems:

Quantified polynomial systems:

Algebraic systems:

Piecewise systems:

Transcendental systems, solvable using inverse functions:

Systems exp-log in the first variable and polynomial in the other variables:

Quantified system:

Systems elementary and bounded in the first variable and polynomial in the other variables:

Quantified system:

Systems analytic and bounded in the first variable and polynomial in the other variables:

Quantified system:

Square systems of analytic equations over bounded regions:

Diophantine Equations  (11)

Linear systems of equations:

Linear systems of equations and inequalities:

Univariate polynomial equations:

Binary quadratic equations:

Thue equations:

Sum of squares equations:

The Pythagorean equation:

Bounded systems of equations and inequalities:

Highdegree systems with no solutions:

Transcendental Diophantine systems:

Polynomial systems of congruences:

Modular Equations  (4)

Linear systems:

Univariate polynomial equations:

Systems of polynomial equations and inequations:

Quantified polynomial systems:

Equations over Finite Fields  (3)

Univariate equations:

Systems of linear equations:

Systems of polynomial equations:

Systems with Mixed Variable Domains  (2)

Mixed real and complex variables:

Mixed real and integer variables:

Systems with Geometric Region Constraints  (9)

Solve over special regions in 2D:

Plot it:

Solve over special regions in 3D:

Plot it:

A quantified system:

An implicitly defined region:

A parametrically defined region:

Derived regions:

Plot it:

Eliminate quantifiers over a Cartesian product of regions:

Regions dependent on parameters:

The answer depends on the parameter value:

Use to specify that is a vector in:

In this case is a vector in:

Generalizations & Extensions  (1)

All variables are solved for:

Options  (28)

Assumptions  (4)

Specify conditions on parameters usingAssumptions:

By default, no solutions that require parameters to satisfy equations are produced:

With an equation on parameters given as an assumption, a solution is returned:

Assumptions that contain solve variables are considered to be a part of the system to solve:

Equivalent statement without usingAssumptions:

With parameters assumed to belong to a discrete set, solutions involving arbitrary conditions are returned:

Cubics  (4)

By default,Solve uses general formulas for solving cubics in radicals only when symbolic parameters are present:

For polynomials with numeric coefficients,Solve does not use the formulas:

WithCubics->False,Solve never uses the formulas:

WithCubics->True,Solve always uses the formulas:

Real roots of irreducible cubics still containI in their algebraic forms bycasus irreducibilis:

Machine-precision numerical evaluation gives a spurious imaginary part:

Arbitrary-precision evaluation still leaves an imaginary part:

With the default settingCubicsAutomatic, explicitly real results are obtained:

GeneratedParameters  (1)

Solve may introduce new parameters to represent the solution:

UseGeneratedParameters to control how the parameters are generated:

InverseFunctions  (3)

By default,Solve uses inverse functions but prints warning messages:

For symbols with theNumericFunction attribute, symbolic inverses are not used:

WithInverseFunctions->True,Solve does not print inverse function warning messages:

Symbolic inverses are used for all symbols:

WithInverseFunctions->False,Solve does not use inverse functions:

Solving algebraic equations does not require using inverse functions:

Here, a method based onReduce is used, as it does not require using inverse functions:

MaxExtraConditions  (4)

By default, no solutions requiring extra conditions are produced:

Unless the parameters are discrete:

The default setting,MaxExtraConditions->0, gives no solutions requiring conditions:

MaxExtraConditions->1 gives solutions requiring up to one equation on parameters:

MaxExtraConditions->2 gives solutions requiring up to two equations on parameters:

Give solutions requiring the minimal number of parameter equations:

Give all solutions:

By default,Solve drops inequation conditions on continuous parameters:

WithMaxExtraConditions->All,Solve includes all conditions:

MaxRoots  (4)

Find out of roots of a polynomial:

Find out of roots of a polynomial system:

Find solutions of a transcendental system:

When the system contains symbolic parameters, the option value is ignored:

Method  (1)

By default,Solve uses inverse functions to solve non-polynomial complex equations:

WithMethod->Reduce,Solve usesReduce to find the complete solution set:

Modulus  (2)

Solve equations over the integers modulo 9:

Find a modulus for which a system of equations has a solution:

Quartics  (3)

By default,Solve uses the general formulas for solving quartics in radicals only when symbolic parameters are present:

For polynomials with numeric coefficients,Solve does not use the formulas:

WithQuartics->False,Solve never uses the formulas:

WithQuartics->True,Solve always uses the formulas:

VerifySolutions  (1)

Solve verifies solutions obtained using non-equivalent transformations:

WithVerifySolutions->False,Solve does not verify the solutions:

Some of the solutions returned withVerifySolutions->False are not correct:

This uses a fast numeric test in an attempt to select correct solutions:

In this case numeric verification gives the correct solution set:

WorkingPrecision  (1)

By default,Solve finds exact solutions of equations:

Computing the solution using 100-digit numbers is faster:

The result agrees with the exact solution in the first 100 digits:

Computing the solution using machine numbers is much faster:

The result is still quite close to the exact solution:

Applications  (7)

Solve a quadratic equation:

Find intersection points of a circle and a parabola:

Find conditions for a quartic to have all roots equal:

A method usingSubresultants:

A method using quantifier elimination:

Plot a space curve given by an implicit description:

Plot the projection of the space curve on the{x,y} plane:

Find a Pythagorean triple:

Find a sequence of Pythagorean triples:

Find how to pay $2.27 postage with 10-, 23-, and 37-cent stamps:

The same task can be accomplished withIntegerPartitions:

Find 200 roots of a complex analytic function:

Show the roots on the complex plot for the function:

Properties & Relations  (15)

Solutions satisfy the equations:

Solutions are given as replacement rules and can be directly used for substitution:

Solve uses{} to represent the empty solution or no solution:

Solve uses{{}} to represent the universal solution or all points satisfying the equations:

For univariate equations,Solve repeats solutions according to their multiplicity:

Solutions of algebraic equations are often given in terms ofRoot objects:

UseN to compute numeric approximations ofRoot objects:

Root objects may involve parameters:

UseSeries to compute series expansions ofRoot objects:

The series satisfies the equation up to order 11:

Solve represents solutions in terms of replacement rules:

Reduce represents solutions in terms of Boolean combinations of equations and inequalities:

Solve uses fast heuristics to solve transcendental equations, but may give incomplete solutions:

Reduce uses methods that are often slower, but finds all solutions and gives all necessary conditions:

UseFindInstance to find solution instances:

LikeReduce,FindInstance can be given inequalities and domain specifications:

UseDSolve to solve differential equations:

UseRSolve to solve recurrence equations:

SolveAlways gives the values of parameters for which complex equations are always true:

The same problem can be expressed usingForAll and solved withSolve orReduce:

Resolve eliminates quantifiers, possibly without solving the resulting quantifier-free system:

Eliminate eliminates variables from systems of complex equations:

This solves the same problem usingResolve:

Reduce andSolve additionally solve the resulting equations:

is bijective iff the equation has exactly one solution for each:

UseFunctionBijective to test whether a function is bijective:

UseFunctionAnalytic to test whether a function is analytic:

An analytic function can have only finitely many zeros in a closed and bounded region:

Possible Issues  (9)

Solve gives generic solutions; solutions involving equations on parameters are not given:

Reduce gives all solutions, including those that require equations on parameters:

WithMaxExtraConditions->All,Solve also gives non-generic solutions:

Solve results do not depend on whether some of the input equations contain only parameters. The following two systems are equivalent and have no generic solutions:

UseMaxExtraConditions to specify the number of parameter conditions allowed:

Use theExists quantifier to find solutions that are valid for some value of parametera:

Solve does not eliminate solutions that are neither generically correct nor generically incorrect:

The solutions are correct for and incorrect for:

For transcendental equations,Solve may not give all solutions:

UseReduce to get all solutions:

Solve withMethod->"Reduce" usesReduce to find solutions, but returns replacement rules:

Using inverse functions allowsSolve to find some solutions fast:

Finding the complete solution may take much longer, and the solution may be large:

This finds the values ofn for whichx==2 is a solution:

Interpretation of assumptions depends on their syntactic properties. Here the solution is generic in the parameter space restricted by the assumptions:

This mathematically equivalent assumption contains the solve variable, and hence is treated as a part of the system to solve:

There are no generic solutions, because the input is interpreted as:

The solution is non-generic, since it requires the parameters to satisfy an equation:

When parameters are restricted to a discrete set, the notion of genericity is not well defined, and all solutions are returned:

Removable singularities of input equations are generally not considered valid solutions:

However, solutions may include removable singularities that are cancelled by automatic simplification:

The removable singularity at is cancelled by evaluation:

Here the removable singularity at is cancelled byTogether, which is used to preprocess the equation:

The value ofMaxRoots is used only for systems with numeric coefficients:

When symbolic parameters are present, the option value is ignored:

Expressions given as variables are treated as atomic objects and not as functions of their subexpressions:

Effectively, variables are replaced with new symbols before the equations are solved:

The result comes from:

See Also

Root Reduce SolveValues FindInstance NSolve FindRoot AsymptoticSolve Eliminate SolveAlways LinearSolve RowReduce ToRadicals GroebnerBasis CylindricalDecomposition DSolve RSolve ContourPlot ContourPlot3D RegionPlot RegionPlot3D GeometricScene

Tech Notes

Related Guides

History

Introduced in 1988(1.0) |Updated in 1996(3.0)2014(10.0)2020(12.2)2024(14.0)

Wolfram Research (1988), Solve, Wolfram Language function, https://reference.wolfram.com/language/ref/Solve.html (updated 2024).

Text

Wolfram Research (1988), Solve, Wolfram Language function, https://reference.wolfram.com/language/ref/Solve.html (updated 2024).

CMS

Wolfram Language. 1988. "Solve." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2024. https://reference.wolfram.com/language/ref/Solve.html.

APA

Wolfram Language. (1988). Solve. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Solve.html

BibTeX

@misc{reference.wolfram_2025_solve, author="Wolfram Research", title="{Solve}", year="2024", howpublished="\url{https://reference.wolfram.com/language/ref/Solve.html}", note=[Accessed: 29-November-2025]}

BibLaTeX

@online{reference.wolfram_2025_solve, organization={Wolfram Research}, title={Solve}, year={2024}, url={https://reference.wolfram.com/language/ref/Solve.html}, note=[Accessed: 29-November-2025]}

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