University of Guilan Journal of Mathematical Modeling 2345-394X 11 3 2023 10 01 Numerical solution of system of nonlinear Fredholm integro-differential equations using CAS wavelets 587 602 6879 10.22124/jmm.2023.24341.2179 EN Mostafa Akrami Arani Department of Applied Mathematics, Faculty of Mathematical Sciences, University of Kashan, Kashan, Iran Mehdi Sabzevari Department of Applied Mathematics, Faculty of Mathematical Sciences, University of Kashan, Kashan, Iran Journal Article 2023 04 18  In this paper, we use the CAS wavelets as basis functions to numerically solve a system of nonlinear Fredholm integro-differential equations. To simplify the problem, we transform the system into a system of algebraic equations using the collocation method and operational matrices. We show the convergence of the presented method and then demonstrate its high accuracy with several illustrative examples. This approach is particularly effective for equations that admit periodic functions because the employed basis CAS functions are inherently periodic. Throughout our numerical examples, we observe that this method provides exact solutions for equations with trigonometric functions at a lower computational cost when compared to other methods. https://jmm.guilan.ac.ir/article_6879_318ee81e228a17a2a8a7139ae08e1693.pdf