H. Rahmatan

Department of Mathematics‎, ‎Payame Noor University‎, ‎P.O‎. ‎Box 19395-3697 Tehran‎, ‎Iran.

[ 1 ] - The norm of pre-Schwarzian derivatives on bi-univalent functions of order $alpha$

‎In the present investigation‎, ‎we give the best estimates for the norm of the pre-Schwarzian derivative $ T_{f}(z)=dfrac{f^{''}(z)}{f^{'}(z)} $ for bi-starlike functions and a new subclass of bi-univalent functions of order $ alpha $‎, ‎where‎ ‎$Vert T_{f} Vert= sup_{|z|

نویسندگان همکار