scholarly journals Coefficient, distortion and growth inequalities for certain p-valent close-to-convex functions

2013 ◽  
Vol 9 (2) ◽  
pp. 57-62
Author(s):  
I.B. Bapana ◽  
Sneha Handwana

Abstract In the present paper, we introduce and investigate a new subclass χtp(γ) of analytic and p-valent close-to-convex functions in the open unit disk U. For functions belonging to the class χtp(γ), some interesting properties including the coefficient estimates, distortion theorems and subordination results are obtained

Author(s):  
Abbas Kareem Wanas

In this paper, by making use the second kind Chebyshev polynomials, we introduce and study a certain class of bi-starlike and bi-convex functions with respect to symmetrical points defined in the open unit disk. We find upper bounds for the second and third coefficients of functions belong to this class.


2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Waggas Galib Atshan ◽  
Ali Hamza Abada

We introduce a subclass of -uniformly convex functions of order with negative coefficients by using the multiplier transformations in the open unit disk . We obtain coefficient estimates, radii of convexity and close-to-convexity, extreme points, and integral means inequalities for the function that belongs to the class .


1998 ◽  
Vol 29 (3) ◽  
pp. 233-244
Author(s):  
H. M. ROSSEN ◽  
H. M. SRIVASTAVA ◽  
M. K. AOUF

The main object of the present paper is to investigate the special classes \[\mathcal P_\alpha^*(p, A, B) \text { and } \mathcal R_\alpha^*(p, A, B) \] \[(0\le \alpha<p; -a\le B<A\le 1; p\in\mathbb{N})\] of analytic and $p$-valent functions in the open unit disk $U$. In particular, various growth and distortion theorems, and several coefficient estimates, are obtained for these as well as related classes of analytic and $p$-valent functions in $\mathcal U$.


Author(s):  
Timilehin G. Shaba ◽  
Amol B. Patil

In the present investigation, we introduce the subclasses $\varLambda_{\Sigma}^{m}(\eta,\leftthreetimes,\phi)$ and $\varLambda_{\Sigma}^{m}(\eta,\leftthreetimes,\delta)$ of \textit{m}-fold symmetric bi-univalent function class $\Sigma_m$, which are associated with the pseudo-starlike functions and defined in the open unit disk $\mathbb{U}$. Moreover, we obtain estimates on the initial coefficients $|b_{m+1}|$ and $|b_{2m+1}|$ for the functions belong to these subclasses and identified correlations with some of the earlier known classes.


Author(s):  
Young Jae Sim ◽  
Oh Sang Kwon

For real numbersαandβsuch that0≤α<1<β, we denote by𝒦α,βthe class of normalized analytic functions which satisfy the following two sided-inequality:α<ℜ1+zf′′z/f′z<β  z∈𝕌,where𝕌denotes the open unit disk. We find some relationships involving functions in the class𝒦(α,β). And we estimate the bounds of coefficients and solve the Fekete-Szegö problem for functions in this class. Furthermore, we investigate the bounds of initial coefficients of inverse functions or biunivalent functions.


Mathematics ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 1334
Author(s):  
Bilal Khan ◽  
Hari M. Srivastava ◽  
Nazar Khan ◽  
Maslina Darus ◽  
Muhammad Tahir ◽  
...  

First, by making use of the concept of basic (or q-) calculus, as well as the principle of subordination between analytic functions, generalization Rq(h) of the class R(h) of analytic functions, which are associated with the leaf-like domain in the open unit disk U, is given. Then, the coefficient estimates, the Fekete–Szegö problem, and the second-order Hankel determinant H2(1) for functions belonging to this class Rq(h) are investigated. Furthermore, similar results are examined and presented for the functions zf(z) and f−1(z). For the validity of our results, relevant connections with those in earlier works are also pointed out.


2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
Edmond Aliaga ◽  
Nikola Tuneski

The class𝒰(λ,μ)of normalized analytic functions that satisfy|(z/f(z))1+μ·f′(z)−1|<λfor allzin the open unit disk is studied and sufficient conditions for anα-convex function to be in𝒰(λ,μ)are given.


2015 ◽  
Vol 65 (3) ◽  
Author(s):  
S. P. Goyal ◽  
Rakesh Kumar

AbstractIn the present paper, we obtain the estimates on initial coefficients of normalized analytic function f in the open unit disk with f and its inverse g = f


2003 ◽  
Vol 2003 (41) ◽  
pp. 2603-2608 ◽  
Author(s):  
Dinggong Yang ◽  
Shigeyoshi Owa

A subclass𝒞p(λ,μ)(p∈ℕ, 0<λ<1, −λ≦μ<1)ofp-valently convex functions in the open unit disk𝕌is introduced. The object of the present paper is to discuss some interesting properties of functions belonging to the class𝒞p(λ,μ).


Filomat ◽  
2017 ◽  
Vol 31 (2) ◽  
pp. 227-245 ◽  
Author(s):  
Najla Alarifi ◽  
Rosihan Ali ◽  
V. Ravichandran

Let f be a normalized analytic function in the open unit disk of the complex plane satisfying zf'(z)/f(z) is subordinate to a given analytic function ?. A sharp bound is obtained for the second Hankel determinant of the kth-root transform z[f(zk)/zk]1/k. Best bounds for the Hankel determinant are also derived for the kth-root transform of several other classes, which include the class of ?-convex functions and ?-logarithmically convex functions. These bounds are expressed in terms of the coefficients of the given function ?, and thus connect with earlier known results for particular choices of ?.


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