چکیده:      
                    
                    
                    The purpose of the present paper is to introduce a class $D_{Sigma ;delta }^{n}C_{0}(alpha )$ of bi-concave functions defined by Al-Oboudi
differential operator. We find estimates on the Taylor-Maclaurin coefficients $leftvert a_{2}rightvert $ and $leftvert a_{3}rightvert$ for functions in this class. Several consequences of these results are also pointed out in the form of corollaries.
                    
                    
                    
                     
                    
                    
                    
                    نوع مطالعه:  
پژوهشي |
                    موضوع مقاله: 
                    
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