Displaying 801 – 820 of 1149

Showing per page

Region of variability for functions with positive real part

Saminathan Ponnusamy, Allu Vasudevarao (2010)

Annales Polonici Mathematici

For γ ∈ ℂ such that |γ| < π/2 and 0 ≤ β < 1, let γ , β denote the class of all analytic functions P in the unit disk with P(0) = 1 and R e ( e i γ P ( z ) ) > β c o s γ in . For any fixed z₀ ∈ and λ ∈ ̅, we shall determine the region of variability V ( z , λ ) for 0 z P ( ζ ) d ζ when P ranges over the class ( λ ) = P γ , β : P ' ( 0 ) = 2 ( 1 - β ) λ e - i γ c o s γ . As a consequence, we present the region of variability for some subclasses of univalent functions. We also graphically illustrate the region of variability for several sets of parameters.

Region of variability for spiral-like functions with respect to a boundary point

S. Ponnusamy, A. Vasudevarao, M. Vuorinen (2009)

Colloquium Mathematicae

For μ ∈ ℂ such that Re μ > 0 let μ denote the class of all non-vanishing analytic functions f in the unit disk with f(0) = 1 and R e ( 2 π / μ z f ' ( z ) / f ( z ) + ( 1 + z ) / ( 1 - z ) ) > 0 in . For any fixed z₀ in the unit disk, a ∈ ℂ with |a| ≤ 1 and λ ∈ ̅, we shall determine the region of variability V(z₀,λ) for log f(z₀) when f ranges over the class μ ( λ ) = f μ : f ' ( 0 ) = ( μ / π ) ( λ - 1 ) a n d f ' ' ( 0 ) = ( μ / π ) ( a ( 1 - | λ | ² ) + ( μ / π ) ( λ - 1 ) ² - ( 1 - λ ² ) ) . In the final section we graphically illustrate the region of variability for several sets of parameters.

Sakaguchi type functions defined by balancing polynomials

Gunasekar Saravanan, Sudharsanan Baskaran, Balasubramaniam Vanithakumari, Serap Bulut (2025)

Mathematica Bohemica

The class of Sakaguchi type functions defined by balancing polynomials has been introduced as a novel subclass of bi-univalent functions. The bounds for the Fekete-Szegö inequality and the initial coefficients | a 2 | and | a 3 | have also been estimated.

Currently displaying 801 – 820 of 1149