Question
Question: The locus of the centres of the circles which cut the circles x<sup>2</sup> + y<sup>2</sup> + 4x –6...
The locus of the centres of the circles which cut the circles
x2 + y2 + 4x –6y + 9 = 0 andx2 + y2 –5x + 4y + 2 = 0 orthogonally is-
A
3x + 4y –5 = 0
B
9x –10y + 7 = 0
C
9x + 10y – 7 = 0
D
9x –10y + 11 = 0
Answer
9x –10y + 7 = 0
Explanation
Solution
The locus of centres of the circles which cut two
circle orthogonally is their radical axis so equation of locus is C1 –C2 = 0
9x – 10y + 7 = 0