# On harmonic univalent functions defined by a generalized Ruscheweyh derivatives operator

## (Lobachevskii Journal of Mathematics, Vol.22, pp.19-26 )

Let SH denote the class of functions f=h+g which are harmonic univalent and sense preserving in the unit disk U. Al-Shaqsi and Darus introduced a generalized Ruscheweyh derivatives operator denoted by Dnλ where Dnλ f(z)= z+ Σk = 2 [1+λ(k-1)]C(n,k)akzk. The authors, using this operators, introduce the class Hnλ of functions which are harmonic in U . Coefficient bounds, distortion bounds and extreme points are obtained.