“…where a(t) = t −1/2 (4/3 − t) −1/2 , f (t,x(t)) = (x(t)) 3 + ln[1 + (x(t)) 2 ], K(t,ζ,x(ζ)) = x(ζ) + ln[1 + (x(ζ)) 3 ]. It can easily be verified that a(t) is nonnegative and pseudo-symmetric about 2/3 on (0,1), f (t,x(t)) and K (t,ζ,x(ζ) 4 = 0. Thus, by Theorem 3.1, there exist extremal positive, concave, and pseudosymmetric solutions for the boundary value problem (3.12).…”