Question

A: The radical centre of the circles $x^2+y^2=4,x^2+y^2-3x=4,x^2+y^2-4y=4$ is (0, 0)
R: Radical centre of three circles is the point of concurrence of the radical axes of the circles taken in pairs.

• A. Both A and R are true and R is the correct explanation of A
• B. Both A and R are true but R is not the correct explanation of A
• C. A is true but R is false
• D. A is false but R is true

Answer 1

The correct option is A Both A and R are true and R is the correct explanation of A

A: radical axis of $s_1$ and $s_2$ is $s_1-s_2=0$
$3x=0\Rightarrow x=0$
and $y=0$
$(0,0)$ is a radical centre of given circles.
R: Radical centre is a point of concurrence of radical axes
of the circles taken in pairs.
So, A and R are both True and R is explanation of A.