A new family of four-step fifteenth-order root-finding methods with high efficiency index

‎In this paper a new family of fifteenth-order methods with high efficiency index is presented‎. This family include four evaluations of the function and one evaluation of its first derivative per iteration.‎ ‎Therefore‎, ‎this family of methods has the efficiency index which equals ۱.۷۱۸۷۷‎. ‎In order to show the applicability and validity of the class‎, ‎some numerical examples are discussed‎.