Question:
Let the latus ractum of the parabola $y=4 x$ be the common chord to the circles $C_{1}$ and $C_{2}$ each of them having radius $2 \sqrt{5}$. Then, the distance between the centres of the circles $C_{1}$ and $C_{2}$ is :
Correct Option: , 2
Solution:
Distance between the centres
$=C_{1} C_{2}=2 C_{1} S=2 \sqrt{20-4}=8$