... ,anda<ρ2b.Weobtainthe existence of at least one solution to problem 1.2 without any growth restrictions on f butan existence assumption of barrier strips. Our proof is based upon the ... leastone solution in C2a, b.3. An Additional Result Parallel to the definition of delta derivative, the notion of nabla derivative was introduced, and the main relations between the two ... 2009.16 J P. Sun and W T. Li, Existence and nonexistence of positive solutions for second-order time scalesystems,” Nonlinear Analysis: Theory, Methods & Applications, vol. 68, no. 10,...