Identity (mathematics) - Definition and Overview

In mathematics, an identity is an equality that remains true regardless of the values of any variables that appear within it.

Identities for classes of functions

• Logarithmic identities
• Exponential identities
• Trigonometric identities
• Hyperbolic function identities
• Hypergeometric function identities
• Combinatorial identities

Named identities

• Bézout's identity
• Euler's identity
• Vandermonde's identity