Approximate Solutions Of Time-fractional Fourth-order Differential Equations With Variable Coefficients

In this work, the homotopy analysis method (HAM) is proposed to obtain semi-analytical solutions of time -fractional fourth-order partial differential equations (PDEs) with variable coefficients, by the Caputo fractional derivative in the time direction. Convergence of this method has been considered and some illustrative ex-amples show the effect of changing homotopy auxiliary parameter h on the convergence of the approximate solution. Comparison of obtained results with other techniques such as Adomian decomposition method and modified variational iteration method, in literature demonstrate that our utilized method is powerful and reliable technique. Moreover, the absolute errors of considered problems in the integer differential order cases, show that the reported results are very closed to the exact solutions.