Two Efficient Methods For Solving Non-linear Fourth-Order PDEs

This paper studies a novel technique based on the use of two effective methods like modified laplacevariational method (mlvim) and a new variational method (mvim)to solve pdes with variable coefficients. the current modification for the (mlvim) is based on coupling of the variational method (vim) and laplace- method (lt). in our proposal there is no need to calculate lagrange multiplier. we applied laplace method to the problem .furthermore, the nonlinear terms for this problem is solved using homotopy method (hpm). some examples are taken to compare results between two methods and to verify the reliability of our present methods.