On a class of functions whose derivatives map the unit disc into a half plane (Q5952805)

Let \(G(a,\delta)\) denote the class of functions \(f\), \(f(0)= f(0)- 1= 0\) for which \(\text{Re } e^{i\alpha}f'(z)> \delta\) in \(D= \{z:|z|< 1\}\) where \(|\alpha|\leq \pi\) and \(\cos\alpha- \delta> 0\). The author gives basic properties of the class including a representation theorem, extremals and argument of \(G(\alpha,\delta)\). Using some results of Silverman and Silvia he also obtains, a coefficients bound for functions in \(G(\alpha,\delta)\) and distortion theorems.