已知A(-2,0),B(2,0),点C,D满足向量AC的模=2,向量AD=1/2(向量AB+向量AC),求点D的轨迹方程

设D(x,y),C(x1,y1)向量AC=(x1+2,y1)向量AD=(x+2,y)向量AB=(4,0)2*向量AD=向量AB+向量AC 即,2(x+2,y)=(4,0)+(x1+2,y1)(2x+4,2y)=(x1+6,y1){x1+6=2x+4{y1=2y-------------------------------{x1+2=2x{y1=2y| 向量AC|=2...