Question
Question: A variable circle passing through point A(a, b) & touching x-axis then locus of centre of such circ...
A variable circle passing through point A(a, b) & touching
x-axis then locus of centre of such circle is
A
(x – a)2 = 4by
B
(y – b)2 = 4ax
C
(x – a)2 = 2by – b2
D
None
Answer
(x – a)2 = 2by – b2
Explanation
Solution
Let centre is C(h, k)
then radii = | k | = CA
̃ (h – a)2 = 2bk – b2