A note on two classes of permutation polynomials over finite fields

Permutation polynomials over finite fields have taken an important role in vast areas in mathematics as well as engineering. Recently, Tu et al. gave some classes of complete permutation polynomials over finite fields of even characteristic. In this paper, we give some properties based on a work of Akbary et al. With the help of the properties, we give extensions of Tu et el.'s results to arbitrary characteristic.