Triple solutions of focal boundary value problems on time scale

We consider the following differential equation on a time scale T, yΔΔ(t)+P(t,y(σ(t)))=0,t∈[a,b]∩T, together with focal boundary conditions, y(a)=0,yΔ(σ(b))=0, where a,b ε T and a < σ (b). By using two different fixed-point theorems, criteria are established for the existence of triple positive solutions of the boundary value problem. We also include some examples to illustrate the results obtained.