In this work, we briefly talk about the incorrect convergence order presented in the paper Khan et al. (Appl. Math. Lett. 25:2262-2266, 2012. Accordingly, we first show that their convergence theorem includes major errors, and it is attempted to provide the correct error equation of their method having fifth-order not eighth-order convergence. Finally, to support our assertion, some numerical examples are tested.Keywords Nonlinear equations Á Iterative methods Á Multipoint methods Á Convergence order
Convergence analysisKhan et al. [1], proposed the following three-step iterative method