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AP EAMCET · Maths · Circle

The ratio of the areas of the concentric circles \(x^2+y^2-\) \(6 x+12 y+15=0\) and \(x^2+y^2-6 x+12 y-15=0\) is

  1. A \(1: \sqrt{2}\)
  2. B \(1: \sqrt{3}\)
  3. C \(1: 2\)
  4. D \(1: 4\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(1: 2\)

Step-by-step Solution

Detailed explanation

Given \(C_1=x^2+y^2-6 x+12 y+15=0\) and \(C_2=x^2+y^2-6 x+12 y-15=0\) \(\Rightarrow r_1=\sqrt{30}\) and \(r_2=\sqrt{60}\) Now ratio of their areas \(=1: 2\)