AP EAMCET201920 Apr 2019Evening ShiftMathematicsCircleActual
If the circle x^2+y^2+6 x-2 y+k=0 bisects the circumference of the circle x^2+y^2+2 x-6 y-15=0 , then k=
Options
- A21
- B-21
- C-23
- D23
Correct answer
C. -23
Step-by-step solution
Equation of given circles array r S₁: x^2+y^2+6 x-2 y+k=0 and S₂: x^2+y^2+2 x-6 y-15=0 array Since, the circle S₁ bisects the circumference of the circle S₂ , then the common of circles S₁ and S₂ will passing through the centre of circle S₂(-1,3) . Equation of common chord of circles S₁ and S₂ is Chord (i) is passes through point (-1,3) , so -4+12+k+15=0 k=-23 Hence, option (c) is correct.