In this work, the Faber polynomial expansions and a different method were employed to estimate the vertical bar a(n)vertical bar coefficients of a subclass of bi-close-to-convex functions, which is introduced by subor...
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In this work, the Faber polynomial expansions and a different method were employed to estimate the vertical bar a(n)vertical bar coefficients of a subclass of bi-close-to-convex functions, which is introduced by subordination concept in the open unit disk. Further, we generalize some of the previous outcomes.
In this paper, we investigate the upper bound associated with the second Hankel determinant H-2(2) for a certain class of bi-close-to-convex functions which we have introduced here. Several closely related results are...
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In this paper, we investigate the upper bound associated with the second Hankel determinant H-2(2) for a certain class of bi-close-to-convex functions which we have introduced here. Several closely related results are also considered.
In 1955, Waadeland considered the class of m-fold aynunetric starlike functions of the form fm(Z) - z + Sigma(infinity)(n=1) a(mn + 1) z(mn+1;) m >= 1;vertical bar z vertical bar < 1 and obtained the sharp coeff...
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In 1955, Waadeland considered the class of m-fold aynunetric starlike functions of the form fm(Z) - z + Sigma(infinity)(n=1) a(mn + 1) z(mn+1;) m >= 1;vertical bar z vertical bar < 1 and obtained the sharp coefficient bounds vertical bar a(mn + 1 vertical bar) <= [(2/m + n - 1)!] / [(n!) (2 / m - 1)!]. Pommerenke in 1962, proved the same coefficient bounds for m-fold symmetric close-to-convexfunctions. Nine years later, Keogh and Miller confirmed the same bounds for the class of symmetric Bazilevic functions. Here we will show that these bounds can be improved even further for the m-fold symmetric bi-close-toconvexfunctions. Moreover, our results improve those corresponding coefficient bounds given by Srivastava et al that appeared in 7(2) (2014) issue of this journal. A function is said to he hi-close-to-convex in a simply connected domain if both the function and its inverse map are close-to-convex there.
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