1 |
2 |
16+16−16 |
圆C2:x2+y2-4x-10y+13=0的圆心C2(2,5),半径r2=
1 |
2 |
16+100−52 |
|C1C2|=
(2+2)2+(5−2)2 |
∵|r1-r2|<|C1C2|<r1+r2,
∴圆C1:x2+y2+4x-4y+4=0与圆C2:x2+y2-4x-10y+13=0相交,
∴圆C1:x2+y2+4x-4y+4=0与圆C2:x2+y2-4x-10y+13=0的公切线有2条.
故选:B.
1 |
2 |
16+16−16 |
1 |
2 |
16+100−52 |
(2+2)2+(5−2)2 |