Title of article :
On partial sums of certain meromophic -valent functions
Author/Authors :
Aouf، نويسنده , , M.K. and Mostafa، نويسنده , , A.O.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2009
Pages :
7
From page :
1325
To page :
1331
Abstract :
In this paper, we study the ratio of meromorphic p -valent functions in the punctured disk U ∗ = { z : 0 < | z | < 1 } of the form f ( z ) = 1 z p + ∑ k = 1 ∞ a k + p − 1 z k + p − 1 to its sequence of partial sums of the form f ( z ) = 1 z p + ∑ k = 1 n + p − 1 a k + p − 1 z k + p − 1 . Also, we determine sharp lower bounds for Re { f ( z ) / f n + p − 1 ( z ) } , Re { f n + p − 1 ( z ) / f ( z ) } , Re { f ′ ( z ) / f n + p − 1 ′ ( z ) } and Re { f n + p − 1 ′ ( z ) / f ′ ( z ) } .
Keywords :
Partial sums , Meromorphic p -valent functions
Journal title :
Mathematical and Computer Modelling
Serial Year :
2009
Journal title :
Mathematical and Computer Modelling
Record number :
1596654
Link To Document :
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