Article
A new proof of the Lagrange multiplier rule
Operations Research Letters. 2016. Vol. 44. No. 3. P. 400-402.
We present an elementary self-contained proof for the Lagrange multiplier rule. It does not refer to any preliminary material 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.