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AP EAMCET · Maths · Circle

If a circle touches the lines \(3 x-4 y-10=0\) and \(3 x-4 y+30=0\) and its centre lies on the line \(x+2 y=0\), then the equation of the circle is

  1. A \(x^2+y^2+4 x-2 y-11=0\)
  2. B \(x^2+y^2+2 x-4 y-11=0\)
  3. C \(x^2+y^2-4 x+2 y-11=0\)
  4. D \(x^2+y^2+2 x-y-11=0\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(x^2+y^2+4 x-2 y-11=0\)

Step-by-step Solution

Detailed explanation

Distance between parallel lines \(3 x-4 y-10=0\) and \(3 x-4 y+30=0\) is the length of diametre of required circle, so radius \[ =\frac{1}{2} \frac{40}{\sqrt{9+16}}=4 \] and mid-point of intersection of lines \(3 x-4 y-10=0, x+2 y=0\) and \(3 x-4 y+30=0\), \(x+2 y=0\), is the…