Solving fractional time-delay diffusion equation with variable-order derivative based on shifted Legendre-Laguerre operational matrices

This article adopts a novel technique to numerical solution for fractional time-delay diffusion equation with variable-order derivative (VFDDEs). As a matter of fact, the variable-order fractional derivative (VFD) that has been used is in the Caputo sense. The first step of this technique is constructive on the construction of the solution using the shifted Legendre-Laguerre polynomials with unknown coefficients. The second step involves using a combination of the collocation method and the operational matrices (OMs) of the shifted Legendre-Laguerre polynomials, as well as the Newton-Cotes nodal points, to find the unknown coefficients. The final step focuses on solving the resulting algebraic equations by employing Newton's iterative method. To illustrate and demonstrate the technique's efficacy and applicability, two examples have been provided.