In the present paper we define some classes of meromorphic functions with fixed argument of coefficients. Next we obtain coefficient estimates, distortion theorems, integral means inequalities, the radii of convexity and starlikeness and convolution properties for the defined class of functions.
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We investigate the family of functions normalized by the condition ƒ(0) = ƒ(0) - 1 = 0, that are analytic in the unit disk, with the property that the domain of values [...] is the disk |z-b| < b, b ≥ 1. Integral and convolution characterizations are found and coefficients bounds are given.
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In this paper we introduce some subclasses of analytic functions with varying argument of coeffcients. These classes are defined in terms of the Hadamard product and generalize the well-known classes of uniformly convex functions. We investigate the coeffcients estimates, distortion properties, radii of starlikeness and convexity for defined classes of functions.
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In the present paper we define a new operator using the generalized Salagean operator and Ruscheweyh operator. Denote by [formula/wzór] the Hadamard product of the generalized Salagean operator [formula/wzór] and Ruscheweyh operator R(n), given by [fomula/wzór] is the class of normalized analytic functions with A1 = A. We study some differential subordinations regarding the operator [formula/wzór].
The main object of the present paper is to investigate some interesting properties of certain meromorphically multivalent functions associated with the extended multiplier transformation.
In this paper we present a new method of determining Koebe domains. We apple this method by giving a new proof of the well-known theorem of A. W. Goodman concerning the Koebe domain for the class T of typically real functions. We applied also the method to determine Koebe sets for classes of the special type , i.e. for TM,g = {∫ ∈ T : ∫(Δ) ⊂ Mg(Δ)}, g ∈ T ∩ S, M > 1, where Δ = {z ∈ C: IzI < 1} and T, S stand for the classes of tipically real functions and univalent functions respectively. In particular, we find the Koebe domains for the class T (M) of all typically real functions with ranges in a given strip.
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Let α, β, γ < and let f, g, h be analytic functions such that Re[f'(z)] ≥ α, Re[g'(z)] ≥ β, Re[h'(z)] ≥ γ in the unit disc U. In this paper we give a sufficient condition for the convexity of Hadamard product f *g *h in the unit dsc U.
Let U = {z is an element of C : \z\ < 1} denote the unit disc and let H = H(U) denote the family of functions holomorphic in U. Let omega denote the class of Schwarz functions w is an element of H such that [...]. We say that / is subordinate to g in U and write [...].
Let D = {z : \z\ < 1} denote the unit disk. For gamma [is not equal to]0, Re[gamma] > 0, we investigate some properties of the differential subordination of the form p{z)+gammazp'\z) [...]P{z), z is an element of D, where P is given by (1.1).
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In this paper we consider the class of functions with negative coefficients denned by differential integral operators. Among others the necessary and sufficient condition for a function f to be in the studied class is presented.
Let delta={z:|z[<1} denote the unit disc. We investigate some properties of a subclas of starlike functions defined by DEF.`. The coefficients of such functions are connected with Fibonacci numbers.
Let H = H(U) be the class of all functions which are holomorphic in the unit disc U = {z : \z[ < 1}. Let P(n,A,B) denotes the class of all functions p(z) = 1 +p1z +p2z2 + ...is an element of H, such that p(z) -< 1+Azn/1-Bzn, where -< denotes subordination. With the class P(n, A, B) we connect the subclass S*(n, A, B) of starlike functions in the following way. A function f(z) = z o+a2z.2 z2 + ... belongs to S*(n, A, B) if and only ifzf'(z)/f(z) is an element of P(n, A, B). In this note we give some estimations for the modulus of functions and coefficients in the classes P(n,A,B) and S*(n,A, B).
Let H = H(U) be the class of all functions which are holomorphic in the unit disc U = {z : \z\ < 1}. Let P(n) denotes the class of all functions p(z) = 1+piz+... is an element H, such thatp(pz) -< (1+zn/(1-zn), where -< denotes subordination. With the class P(n) we connect the subclass S*(n) of starlike functions in the following way. A function f(z) = z + a2z + ... belongs to S* (n) if and only if zf'(z)/f(z) is an element of P(n). In this note we give the estimations of some coefficients in the classes P(n) and S*(n) and we find the radius of convexity of the class S*(n).