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AP EAMCET2004MathematicsCircle

The centre of the circle r^2-4 r( + )-4=0 in cartesian coordinates is

Options

  1. A(1,1)
  2. B(-1,-1)
  3. C(2,2)
  4. D(-2,-2)

Correct answer

C. (2,2)

Step-by-step solution

Put x=r and y=r r^2=x^2+y^2 From Eqs. (i) array lrl & r^2-4(r +r )-4 & =0 & x^2+y^2-4(x+y)-4 & =0 & x^2+y^2-4 x-4 y-4 & =0 & Centre of circle (2,2) . array

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