A note on some new iterative methods with third-order convergence

In [J.H. Chen, Some new iterative methods with three-order convergence, Appl. Math. Comput. 181 (2006) 1519–1522], some new iterative methods were proposed and proved to be third-order convergence. In this paper, some mistakes are pointed out in the derivation of these new methods. An analysis is given to show that these new iterative methods converge only linearly.