$\begin{array}{1 1} (a)\;\bigg(\large\frac{-\sqrt 3}{2},\frac{1}{2} \bigg)\\ (b)\;\bigg(\large\frac{\sqrt 3}{2},\frac{-1}{2} \bigg)\\
(c)\;\bigg(\large\frac{-\sqrt 3}{4},\frac{1}{2} \bigg)\\
(d)\;\bigg(\large\frac{-\sqrt 3}{2},\frac{1}{7} \bigg)
\end{array} $