Published online by Cambridge University Press: 20 November 2018
In the theory of the asymptotic solution or stability of ordinary differential equations most attention has been given to linear or nearly-linear cases. Investigations in this field, starting primarily with those of Kneser (7) on the equation y″ + f(x)y = 0, have by now mostly been summed up in results on the vector-matrix system dy/dx = Ay + f (y, x), where y and f denote n-vectors of functions, and A an n-by-n matrix, frequently assumed constant.