If the equation of a circle is λx2 + (2λ – 3)y2 – 4x + 6y – 1 = 0, then the coordinates of centre are
Given that the equation of the circle is:
⇒ λx2 + (2λ - 3)y2 - 4x + 6y - 1 = 0 ..... (1)
Comparing with the standard equation of circle:
⇒ x2 + y2 + 2ax + 2by + c = 0
We get
⇒ λ = 2λ - 3
⇒ 2λ - λ = 3
⇒ λ = 3
Substituting λ value in (1), we get
⇒ 3x2 + (2(3) - 3)y2 - 4x + 6y - 1 = 0
⇒ 3x2 + 3y2 - 4x + 6y - 1 = 0
⇒
We know that for a circle x2 + y2 + 2ax + 2by + c = 0
⇒ Centre = (- a, - b)
⇒ Radius =
⇒ Centre(C) =
⇒
∴The correct option is (b)