E. Zeynal - Department of Applied Mathematics, Yadegar-e-Imam Khomeini Shahre Rey Branch, Islamic Azad University, Tehran, Iran.
E. Babolian - Department of Mathematical Sciences and Computer, Kharazmi University, Tehran, ‎Iran‎.
T. Damercheli - Department of Mathematics, Yadegar-e-Imam Khomeini Shahre Rey Branch,Islamic Azad University, Tehran, Iran.

In this paper, we propose direct methods to solve linear delay differential equations (DDEs) based on vector forms of Block-Pulse Functions (BPFs) and Triangular Functions (TFs). Operational matrix of integration of BPFs and TFs are applied to transform LDDE to a linear system of algebraic equations. Further, some numerical examples are presented to indicate the reliability and accuracy of these methods. Convergence analysis of the present method has been discussed.

معادلات تاخیری خطی, توابع بلاک پالس, توابع مثلثی, روش مستقیم