Identity (Equation)/Examples/Square of Sum

Example of Identity in context of Equations

The result Square of Sum:

$\forall x, y \in \R: \paren {x + y}^2 = x^2 + 2 x y + y^2$

is an example of an identity.

Sources

• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): equation
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): equation