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

## (*Lobachevskii Journal of Mathematics, Volume XXII*)

Let *S*_{H} 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 *D*^{n}_{λ}
where *D*^{n}_{λ}
f(z)= z+ Σ_{k = 2}^{∞}
[1+λ(k-1)]C(n,k)a_{k}z^{k}.
The authors, using this operators, introduce the class
*H*^{n}_{λ} of functions which are harmonic in
*U* . Coefficient bounds, distortion bounds and extreme
points are obtained.