Abstract :
In this paper, by combining a new maximum principle and the theory of the
two-parameter linear eigenvalue problem, we develop the monotone method in the
presence of lower and upper solutions for the problem
u 4. x.sf x,u x., uY x.., 0-x-1,
u 0. su 1. suY 0. suY 1. s0,
where f :w0,1x=R=RªR is continuous
