We present an elementary self-contained proof for the Lagrange multiplier rule. It does not refer to any substantial preparations and it is only based on the observation that a certain limit is positive. At the end of this note, the power of the Lagrange multiplier rule is analyzed.

Econometric Institute Research Papers
Erasmus School of Economics

Brinkhuis, J., & Protassov, V. (2015). A new proof of the Lagrange multiplier rule (No. EI2015-39). Econometric Institute Research Papers. Retrieved from http://hdl.handle.net/1765/79540