KCET2009MathematicsCircle
The coordinates of the centre of the smallest circle passing through the origin and having y = x +1 as a diameter are
Options
- A( 1 2 , -1 2 )
- B( 1 2 , 1 3 )
- C(-1,0)
- D(- 1 2 , 1 2 )
Correct answer
D. (- 1 2 , 1 2 )
Step-by-step solution
The smallest circle means that its radial is, distance from origin to the diameter is smallest. Let equation of line perpendicular to y-x=1 is x + y = . Also, it passes through (0,0) . =0 Perpendicular line is x + y =0 . The intersection point of lines are (- 1 2 , 1 2 ) . Which is the centre of circle.