“…The homotopy perturbation method [4][5][6][7][8][9][10][11]15,[24][25][26][27]43,44,47,55] constructs an effective iteration algorithm by guaranteeing its iteration path from the initial guess to the exact solution. The variational iteration method [29,32,35,51] adopts the variational theory [33,34] to find an optimal iteration formulation for differential equations. Taylor's series method [20,23] is simple, but only an infinite series solution is useful for analysis of a complex nonlinear problem.…”