The expression \( m^2 + n^2 \) represents the sum of the squares of two variables, \( m \) and \( n \). It is a common expression in mathematics and can be used in various contexts, such as in geometry (for example, the Pythagorean theorem) or in algebra.
If you have specific values for \( m \) and \( n \), you can substitute them into the expression to calculate a numerical result. For example, if \( m = 3 \) and \( n = 4 \):
\[ m^2 + n^2 = 3^2 + 4^2 = 9 + 16 = 25 \]
If you have a particular context or values for \( m \) and \( n \) in mind, please provide them, and I’d be happy to assist further!