Advances in Difference Equations
Volume 2010 (2010), Article ID 143298, 8 pages
doi:10.1155/2010/143298
  
     
          
          On connection between second-order delay differential equations and integrodifferential equations with delay
          
            Leonid Berezansky1
            , Josef Diblík
             and Zdenĕk Šmarda3
          
          1Department of Mathematics, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
          
          3Department of Mathematics, Faculty of Electrical Engineering and Communication, 61600, Brno University of Technology, Brno, Czech Republic
          
          Abstract
The existence and uniqueness of solutions and a representation of solution formulas are studied for the following initial value problem: x˙(t)+∫t0tK(t,s)x(h(s))ds=f(t),  t≥t0,  x∈ℝn, x(t)=φ(t), t<t0. Such problems are obtained by transforming second-order delay differential equations x¨(t)+a(t)x˙(g(t))+b(t)x(h(t))=0 to first-order differential equations.