Problems Concerning Coefficients of Symmetric Starlike Functions Connected with the Sigmoid Function

Initial coefficients of starlike functions with real coefficients

The sharp bounds for the third and fourth coefficients of Ma-Minda starlike functions having fixed second coefficient are determined. These results are proved by using certain constraint coefficient problem for functions with positive real part whose coefficients are real and the first coefficient is kept fixed. Analogous results are obtained for a general class of close-to-convex functions

On a Subclass of Certain Starlike Functions with Negative Coefficients

A certain subclass TΩ(n, p, λ, α)of starlike functions in the unit disk is introduced. The object of the present paper is to derive several interesting properties of functions belonging to the class TΩ(n, p, λ, α). Coefficient inequalities, distortion theorems and closure theorems of functions belonging to the class TΩ(n, p, λ, α) are determined. Also we obtain radii of convexity for the class ...

Starlike Functions of order α With Respect To 2(j,k)-Symmetric Conjugate Points

In this paper, we introduced and investigated starlike and convex functions of order α with respect to 2(j,k)-symmetric conjugate points and coefficient inequality for function belonging to these classes are provided . Also we obtain some convolution condition for functions belonging to this class.

On a Certain Subclass of Starlike Functions with Negative Coefficients

We introduce the class H(α, β) of analytic functions with negative coefficients. In this paper we give some properties of functions in the class H(α, β) and we obtain coefficient estimates, neighborhood and integral means inequalities for the function f(z) belonging to the class H(α, β). We also establish some results concerning the partial sums for the function f(z) belonging to the class H(α,...

On Meromorphic Harmonic Starlike Functions with Missing Coefficients