question_answer

A circle touches the X-axis and also touches the circle with centre at (0, 3) and radius 2. The locus of the centre of the circle is       AIEEE  Solved  Paper-2005

A) a parabola        

B)        a hyperbola       

C)        a circle            

D)        an ellipse

Correct Answer: A

Solution :

Since, circle touches the X-axis and also touches circle with the centre at (0, 3) and radius 2, then             Locus of centre of circle is                     This equation represents a parabola. Thus, locus of the centre of the circle is a parabola.