Coefficient bounds for certain classes of meromorphic functions

Abstract

Sharp bounds for | a 1 - a 0 2 | are derived for certain classes () and () of meromorphic functions f(z) defined on the punctured open unit disk for which - z f ′ (z) / f(z) and (-(1-2)z f ′ (z)+ z 2 f (z)) / ((1-) f(z)-z f ′ (z)) (-(0,1 ];()≥0), respectively, lie in a region starlike with respect to 1 and symmetric with respect to the real axis. Also, certain applications of the main results for a class of functions defined through Ruscheweyh derivatives are obtained.