7.
如图\(1\),在平面直角坐标系中,\(A(a,0)\),\(B(b,3)\),\(C(4,0)\),且满足\((a+b)^{2}+|a-b+6|=0\),线段\(AB\)交\(y\)轴于\(F\)点.
\((1)\)求点\(A\)、\(B\)的坐标.
\((2)\)点\(D\)为\(y\)轴正半轴上一点,若\(ED/\!/AB\),且\(AM\),\(DM\)分别平分\(∠CAB\),\(∠ODE\),如图\(2\),求\(∠AMD\)的度数.
\((3)\)如图\(3\),\((\)也可以利用图\(1)\)
\(①\)求点\(F\)的坐标;
\(②\)点\(P\)为坐标轴上一点,若\(\triangle ABP\)的三角形和\(\triangle ABC\)的面积相等?若存在,求出\(P\)点坐标.