释义 |
Lagrange MultiplierUsed to find the Extremum of subject to the constraint ,where and are functions with continuous first Partial Derivatives on the OpenSet containing the curve , and at any point on the curve(where is the Gradient). For an Extremum to exist,
 | (1) |
But we also have
 | (2) |
Now multiply (2) by the as yet undetermined parameter and add to (1),
 | (3) |
Note that the differentials are all independent, so we can set any combination equal to 0, and the remainder must stillgive zero. This requires that
 | (4) |
for all , ..., . The constant is called the Lagrange multiplier. For multiple constraints, , , ...,
 | (5) |
See also Kuhn-Tucker Theorem References
Arfken, G. ``Lagrange Multipliers.'' §17.6 in Mathematical Methods for Physicists, 3rd ed. Orlando, FL: Academic Press, pp. 945-950, 1985.
|