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AP EAMCET · Maths · Circle

If the chord \(x+y=1\) of the circle \(x^2+y^2=a^2\) subtends a right angle at the origin, then \(a=\)

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

Answer & Solution

Correct Answer

(C) 1

Step-by-step Solution

Detailed explanation

\(x^2+y^2=a^2(x+y)^2\) \((1-a^2)x^2-2a^2xy+(1-a^2)y^2=0\) \((1-a^2)+(1-a^2)=0\) \(2(1-a^2)=0\) \(a^2=1\) \(a=1\)