如图,在平面直角坐标系\(xOy\)中,椭圆\(C\)过点\(( \sqrt {3}, \dfrac {1}{2})\),焦点\(F_{1}(- \sqrt {3},0)\),\(F_{2}( \sqrt {3},0)\),圆\(O\)的直径为\(F_{1}F_{2}\).
\((1)\)求椭圆\(C\)及圆\(O\)的方程;
\((2)\)设直线\(l\)与圆\(O\)相切于第一象限内的点\(P\).
\(①\)若直线\(l\)与椭圆\(C\)有且只有一个公共点,求点\(P\)的坐标;
\(②\)直线\(l\)与椭圆\(C\)交于\(A\),\(B\)两点\(.\)若\(\triangle OAB\)的面积为\( \dfrac {2 \sqrt {6}}{7}\),求直线\(l\)的方程.