In this paper the authors study (1-γ+zf(?)(z)/f'(z))/(zf'(z)/f(z)) as a criteria for starlikeness and convexity. Sharp upper bound of |α2| and of the Fekete-Szego functional |α3-μα22| is given for a class...In this paper the authors study (1-γ+zf(?)(z)/f'(z))/(zf'(z)/f(z)) as a criteria for starlikeness and convexity. Sharp upper bound of |α2| and of the Fekete-Szego functional |α3-μα22| is given for a class of analytic functions defined by using this expression.展开更多
文摘In this paper the authors study (1-γ+zf(?)(z)/f'(z))/(zf'(z)/f(z)) as a criteria for starlikeness and convexity. Sharp upper bound of |α2| and of the Fekete-Szego functional |α3-μα22| is given for a class of analytic functions defined by using this expression.