TY - JOUR
T1 - Sufficient conditions for Janowski starlike functions with fixed second coefficient
AU - Alarifi, Najla M.
N1 - Publisher Copyright:
© 2022, African Mathematical Union and Springer-Verlag GmbH Deutschland, ein Teil von Springer Nature.
PY - 2022/12
Y1 - 2022/12
N2 - Let A, B, D, E∈ [- 1 , 1] and let p(z) be an analytic function with fixed initial coefficient defined in the open unit disk. Conditions on A, B, D, and E are determined so that 1 + αzp′(z) being subordinated to (1 + Dz) / (1 + Ez) implies that p(z) is subordinated to (1 + Az) / (1 + Bz) and other similar implications involving 1 + αzp′(z) / p(z) , αp2(z) + λzp′(z) , αp(z) + (1 - α) p2(z) + λzp′(z) , and (1 - α) p(z) + α(1 + zp′(z) / p(z)). Also, sufficient conditions for Janowski starlikeness with fixed second coefficient are obtained.
AB - Let A, B, D, E∈ [- 1 , 1] and let p(z) be an analytic function with fixed initial coefficient defined in the open unit disk. Conditions on A, B, D, and E are determined so that 1 + αzp′(z) being subordinated to (1 + Dz) / (1 + Ez) implies that p(z) is subordinated to (1 + Az) / (1 + Bz) and other similar implications involving 1 + αzp′(z) / p(z) , αp2(z) + λzp′(z) , αp(z) + (1 - α) p2(z) + λzp′(z) , and (1 - α) p(z) + α(1 + zp′(z) / p(z)). Also, sufficient conditions for Janowski starlikeness with fixed second coefficient are obtained.
KW - Analytic function
KW - Fixed second coefficient
KW - Subordination
UR - https://www.scopus.com/pages/publications/85142529636
U2 - 10.1007/s13370-022-01034-4
DO - 10.1007/s13370-022-01034-4
M3 - Article
AN - SCOPUS:85142529636
SN - 1012-9405
VL - 33
JO - Afrika Matematika
JF - Afrika Matematika
IS - 4
M1 - 99
ER -