Ding-Gong Yang

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Let Rp denote the class of functions normalized by 0096-3 doi:10. * Co E-m f ðzÞ 1⁄4 z p þ X1 n1⁄41 anz p ðp 2 N :1⁄4 f1; 2; 3; . . .gÞ; which are analytic and p-valent in 0 < jzj < 1. Making use of a linear operator, which is defined here by means of the Hadamard product (or convolution), we introduce some new subclasses of the meromorphically p-valent(More)
Let Ss(α) (0≤α< 1/2) be the class of functions f(z)= z+··· which are analytic in the unit disk and satisfy there Re{zf ′(z)/(f (z)−f(−z))} > α. In the present paper, we find the sharp lower bound on Re{(f (z)−f(−z))/z} and investigate two subclasses S0(α) and T0(α) of Ss(α). We derive sharp distortion inequalities and some properties of the partial sums for(More)
Let Ap(p ∈ N) be the class of functions f(z) = z + ∑∞ m=1 ap+mz p+m which are analytic in the unit disk. By virtue of the Ruscheweyh derivatives we introduce the new subclasses Cp(n, α, β, λ, μ) of Ap. Subordination relations, inclusion relations, convolution properties and a sharp coefficient estimate are obtained. We also give a sufficient condition for a(More)
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