Editing Costate equation (section)

== Interpretation ==
The costate variables <math>\lambda(t)</math> can be interpreted as [[Lagrange multipliers]] associated with the state equations.  The state equations represent constraints of the minimization problem, and the costate variables represent the [[marginal cost]] of violating those constraints; in economic terms the costate variables are the [[shadow price]]s.<ref>{{cite book |first=Akira |last=Takayama |title=Mathematical Economics |publisher=Cambridge University Press |year=1985 |page=621 |url=https://books.google.com/books?id=j6PLOBFotPQC&pg=PA621 |isbn=9780521314985 }}</ref><ref>{{cite journal |first=Daniel |last=Léonard |title=Co-state Variables Correctly Value Stocks at Each Instant : A Proof |journal=Journal of Economic Dynamics and Control |volume=11 |issue=1 |year=1987 |pages=117–122 |doi=10.1016/0165-1889(87)90027-3 }}</ref>