The well-known Ilieff-Sendov
conjecture asserts that for any polynomial p(z) = XTk=l{z−zk) with ∖zk∖← 1, each
of the disks. ∖z − zk∖≤ 1(1 ≤ k ≤ n) must contain a critical point of p. This
conjecture is proved for polynomials of arbitrary degree n with at most four distinct
zeros. This extends a result of Saff and Twomey.