利用上下解方法给出了一类四阶微分方程奇异边值问题有C^2[0,1]和C3[0,1]正解的充分条件.
This paper investigates a class of boundary value problems for fourth-order singular differential equations. We give a sufficient condition for the existence of positive C^2[0, 1] solutions and positive C^3[0, 1] solutions by using the method of lower and upper solutions.