Comparison and Integral Comparison Theorems for Linear Differential Equations

Comparison theorems are developed for the equation Ly + q(x)y = 0, where L is a linear disconjugate differential operator of order n, n ≥ 2, and q(x) is a continuous function of one sign. The criteria include, as special cases, some direct and integral comparison results previously obtained. By the same criteria we settle a question posed by Butler and Erbe.