ExamBro
ExamBro
TS EAMCET · Maths · Circle

If \((-1,-1)\) is the radical centre of the circles \(x^2+y^2+\) \(2 g x-4 y+4=0, x^2+y^2+6 x+2 f y+12=0\) and \(x^2+y^2\) \(+10 y+20=0\) then \(g-f=\)

  1. A 0
  2. B -1
  3. C 1
  4. D 2
Verified Solution

Answer & Solution

Correct Answer

(C) 1

Step-by-step Solution

Detailed explanation

Here from circles \(\mathrm{I}^{\mathrm{st}}\) and \(\mathrm{II}^{\mathrm{nd}}\) \[ \begin{aligned} & x^2+y^2+2 g x-4 y+4-x^2-y^2-6 x-2 \text { of } y-12=0 \\ & (2 g-6) x-(4+2 f) y-8=0 \end{aligned} \] \(\because\) We are given that radical centre of three circles are…