TODD, J. (1) Determinants and Matrices (2) Theory of Equations (3) Integration (4) Vector Methods: Applied to Differential Geometry, Mechanics and Potential Theory (5 ...

We determine the general solution of the functional equation $f(x + y) + f(x - y) = A(y)f(x)\quad (x, y \in G),$ where G is a 2-divisible abelian group, f is a vector ...