解:将C2代入C1得6x=4,x=2/3再把x=2/3代入方程求得y值,y=±4√2/3。所以交点坐标为(2/3,4√2/3),(2/3,-4√2/3),有过点P(-2,4)设圆的方程为x^2+y^2+dx+ey+f=0所以{4/9+32/9+2/3d+4√2/3e+f=0{4/9+32/9+2/3d-4√2/3e+f=0{4+16-2d+4e+f=0解:d=6,e=0,f=-8,所以交点的圆的方程为:x^2+y^2+6x-8=0