x2+y2-2x+2y-2=0(x-1)²+(y+1)²=4;圆心为(1,-1)半径=2；所以设切线为k=(y-1)/(x-4);即kx-y-4k+1=0;圆心到切线距离d=|k+1-4k+1|/√(k²+1)=2;(2-3k)²=4(k²+1);9k²-12k+4=4k²+4;5k&#...有个人答案是 24Ｘ-9Ｙ-91=0