noun
functional equation
A mathematical equation in which the unknown is a function. Used in analysis, number theory, and related fields.
コーシーの関数方程式は、f(x+y)=f(x)+f(y) の形で表される。
Cauchy's functional equation is expressed in the form f(x+y)=f(x)+f(y).
微分方程式 (differential equation) involves derivatives of an unknown function, while 関数方程式 (functional equation) relates the function's values at different points without necessarily involving derivatives.
Compound of 関数 (function) and 方程式 (equation), directly corresponding to the English term 'functional equation'.