ISSN : 1226-0657
Different versions of the boundary Schwarz lemma for the 𝒩 (𝜌) class are discussed in this study. Also, for the function g(z) = z+b<sub>2</sub>z<sup>2</sup>+b<sub>3</sub>z<sup>3</sup>+... defined in the unit disc D such that g ∈ 𝒩 (𝜌), we estimate a modulus of the angular derivative of g(z) function at the boundary point 1 ∈ 𝜕D with g'(1) = 1 + 𝜎 (1 - 𝜌), where <TEX>${\rho}={\frac{1}{n}}{\sum\limits_{i=1}^{n}}g(c_i)={\frac{g^{\prime}(c_1)+g^{\prime}(c_2)+{\ldots}+g^{\prime}(c_n)}{n}}{\in}g^{\prime}(D)$</TEX> and 𝜌≠1, 𝜎 > 1 and c<sub>1</sub>, c<sub>2</sub>, ..., c<sub>n</sub> ∈ 𝜕D. That is, we shall give an estimate below |g"(1)| according to the first nonzero Taylor coefficient of about two zeros, namely z = 0 and z ≠ 0. Estimating is made by using the arithmetic average of n different derivatives g'(c<sub>1</sub>), g'(c<sub>2</sub>), ..., g'(c<sub>n</sub>).