Question

A variable chord is drawn through the origin to the circle x² + y² – 2ax = 0. The locus of the centre of the circle drawn on this chord as diameter is

• A. x² + y² + ax = 0
• B. x²+ y² + ay = 0
• C. x²+ y² – ax = 0
• D. x² + y² – ay = 0

Answer 1

Answer: (C)

x²+ y² – ax = 0

Answer 2

Let circle is S + lL = 0 where S ŗ x² + y² – 2ax = 0

and L ŗ mx – y = 0, line L = 0 is diameter of this circle.