Two types of permutation polynomials with special forms

Let q be a power of a prime and F-q be a finite field with q elements. In this paper, we propose four families of infinite classes of permutation trinomials having the form cx-x(s)+x(qs), and investigate the relationship between two types of widely discussed permutation polynomials. Based on this relation, many classes of permutation polynomials having the form (x(qk) - x + delta)(s) + cx without restriction on delta are derived. (C) 2018 Elsevier Inc. All rights reserved.