Cassinian Focal-Directorial Curves

In this paper, we introduce new plane curves, i.e. Cassinian focal-directorial curves as curves of a transitory type, of Cassinian multidirectorial curves as counterpart to Cassinian multifocal curves; and demonstrate their geometric genesis, and their form variation for special choices of foci and directrices. The form variation of Cassinian focal-directorial curves (CFDC) for different values of the particular parameter is also considered. Furthermore, it is shown that these algebraic curves also might have applications in architectural space design.