A note on the paper "Tang et al. [Bull Iran Math Soc (2019) doi:10.1007/s41980-019-00262-y]"

Abstract

Very recently Tang et al. [Bull Iran Math Soc (2019) doi:10.1007/s41980-019-00262-y] have studied some majorization results for two certain subclasses of the starlike functions associated with the sine and cosine functions defined by $\mathcal{S}^*_s$ and $\mathcal{S}^*_c$, respectively. In this note we pointed out that the definition of the class $\mathcal{S}^*_c$ and it's result are incorrect and give correct definition and result.