implicit function theorem
E3650
The implicit function theorem is a fundamental result in calculus and differential geometry that guarantees, under suitable smoothness and nondegeneracy conditions, the local solvability of equations for some variables as differentiable functions of others.
Observed surface forms (1)
| Surface form | Occurrences |
|---|---|
| submersion theorem | 1 |
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf | mathematical theorem ⓘ |
| appliesTo | equations F(x,y)=0 ⓘ |
| assumes |
C1 regularity
ⓘ
Jacobian matrix with nonzero determinant ⓘ continuously differentiable function ⓘ nondegeneracy conditions ⓘ sufficient smoothness conditions ⓘ |
| concerns |
differentiable functions
ⓘ
implicit equations ⓘ local solvability of equations ⓘ systems of equations ⓘ |
| concludes | existence of y=g(x) near a point ⓘ |
| ensures |
continuity of the implicit function
ⓘ
continuous differentiability of the implicit function ⓘ |
| field |
calculus
ⓘ
differential geometry ⓘ multivariable calculus ⓘ nonlinear analysis ⓘ real analysis ⓘ |
| generalizes | inverse function theorem ⓘ |
| guarantees |
differentiability of the implicit function
ⓘ
existence of local solutions ⓘ local representation of variables as functions of others ⓘ uniqueness of the local solution under given conditions ⓘ |
| hasApplication |
comparative statics in economics
ⓘ
coordinate charts on manifolds ⓘ defining smooth submanifolds as level sets ⓘ local parametrization of solution sets ⓘ |
| hasVersion |
Banach space implicit function theorem
ⓘ
complex implicit function theorem ⓘ real implicit function theorem ⓘ |
| implies | inverse function theorem in special cases ⓘ |
| isUsedIn |
differential geometry
ⓘ
dynamical systems ⓘ economics ⓘ manifold theory ⓘ nonlinear equation solving ⓘ optimization theory ⓘ partial differential equations ⓘ theory of submanifolds ⓘ |
| logicalForm | local existence and uniqueness theorem ⓘ |
| relatedTo |
constant rank theorem
ⓘ
rank theorem ⓘ implicit function theorem self-linksurface differs ⓘ
surface form:
submersion theorem
|
| requires |
F(a,b)=0 at a base point (a,b)
ⓘ
Jacobian with respect to dependent variables invertible at (a,b) ⓘ |
| typicalAssumption | F is Ck with k≥1 ⓘ |
| typicalConclusion | implicit function is Ck with k≥1 ⓘ |
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
submersion theorem