On convex and starlike univalent functions

Convex and Starlike Univalent Functions

Generating Starlike and Convex Univalent Functions

Alexander [1] was the first to introduce certain subclasses of univalent functions examining the geometric properties of the image f(D) of D under f . The convex functions are those that map D onto a convex set. A function w = f(z) is said to be starlike if, together with any of its points w, the image f(D) contains the entire segment {tw : 0 ≤ t ≤ 1}. Thus we introduce the denotations S = {f ∈...

Some Results on Starlike and Convex Functions

Let A denotes the class of functions f(z) that are analytic in the unit disk U = {z : |z| < 1} and normalized by f(0) = f ′(0)− 1 = 0. Further, let f, g ∈ A. Then we say that f(z) is subordinate to g(z), and we write f(z) ≺ g(z), if there exists a function ω(z), analytic in the unit disk U , such that ω(0) = 0, |ω(z)| < 1 and f(z) = g(ω(z)) for all z ∈ U . Specially, if g(z) is univalent in U t...

Coefficient estimates for bi-univalent Ma-Minda starlike and convex functions

Estimates on the initial coefficients are obtained for normalized analytic functions f in the open unit disk with f and its inverse g = f satisfying the conditions that zf (z)/f(z) and zg(z)/g(z) are both subordinate to a starlike univalent function whose range is symmetric with respect to the real axis. Several related classes of functions are also considered, and connections to earlier known ...

Horadam Polynomials Estimates for $lambda$-Pseudo-Starlike Bi-Univalent Functions

In the present investigation, we use the Horadam Polynomials to establish upper bounds for the second and third coefficients of functions belongs to a new subclass of analytic and $lambda$-pseudo-starlike bi-univalent functions defined in the open unit disk $U$. Also, we discuss Fekete-Szeg$ddot{o}$ problem for functions belongs to this subclass.