Question

If 2x-4y-9=0 & 6x-12y+7=0
are tangents to same circle then R=?

Answer 1

@ParthKohli @rajathsbhat

Answer 2

yahan par inhone 2r=|P1-P2| kiya hai why did they subtract:/

Answer 3

yeah i remember doing it that way. But I'm not sure why....
lemme think..

Answer 4

Hmm.. Not sure if this way works!
2x-4y-9=0 & 6x-12y+7=0 = tangents to the same circle.
That have the same slope => perpendicular distance between the two lines is the diameter of the circle. Half of the diameter is the radius :\
I think this is not a smart way to solve your problem though :(

Answer 5

as @Callisto rightly stated..the lines are parallel, distance between them gives diameter, half of diameter is radius! voila !