5.
设圆\(x^{2}+y^{2}+2x-15=0\)的圆心为\(A\),直线\(l\)过点\(B(1,0)\)且与\(x\)轴不重合,\(l\)交圆\(A\)于\(C\),\(D\)两点,过\(B\)作\(AC\)的平行线交\(AD\)于点\(E\).
\((\)Ⅰ\()\)证明\(|EA|+|EB|\)为定值,并写出点\(E\)的轨迹方程;
\((\)Ⅱ\()\)设点\(E\)的轨迹为曲线\(C_{1}\),直线\(l\)交\(C_{1}\)于\(M\),\(N\)两点,过\(B\)且与\(l\)垂直的直线与圆\(A\)交于\(P\),\(Q\)两点,求四边形\(MPNQ\)面积的取值范围.