Lagrange's theorem

In mathematics, Lagrange's theorem usually refers to any of the following theorems, attributed to Joseph Louis Lagrange:


 * Lagrange's theorem (group theory)
 * Lagrange's theorem (number theory)
 * Lagrange's four-square theorem, which states that every positive integer can be expressed as the sum of four squares of integers
 * Mean value theorem in calculus
 * The Lagrange inversion theorem
 * The Lagrange reversion theorem
 * The method of Lagrangian multipliers for mathematical optimization