TY - JOUR AU - Abdullah, Habeeb Kareem AU - Haydar, Amal Khalaf AU - Obead, Kawther Reyadh PY - 2020 TI - Characteristic roots of a second order retarded functional differential equation via spectral-tau method JO - Journal of Nonlinear Sciences and Applications SP - 147--153 VL - 13 IS - 3 AB - In this paper, we have found the solution of second-order delay differential equations of retarded type with multiple delays. As well as developing an approximation for finding characteristic roots for such delay differential equations via the method of spectral tau which depends on the basis mixed Fourier basis or shifted Chebyshev polynomials. SN - ISSN 2008-1901 UR - http://dx.doi.org/10.22436/jnsa.013.03.03 DO - 10.22436/jnsa.013.03.03 ID - Abdullah2020 ER -