2.
已知圆\(C\):\(x\)\({\,\!}^{2}+\)\(y\)\({\,\!}^{2}+2\)\(x\)\(+\)\(a\)\(=0\)上存在两点关于直线\(l\):\(mx\)\(+\)\(y\)\(+1=0\)对称.
\((1)\)求实数\(m\)的值;
\((2)\)若直线\(l\)与圆\(C\)交于\(A\),\(B\)两点,\(\overrightarrow{OA}\bullet \overrightarrow{OB}=-3(\)\(O\)为坐标原点\()\),求圆\(C\)的方程.