CircleHard
Question
The number of common tangents to the circle
x2 + y2 - 4x - 6y - 12 = 0 and
x2 + y2 + 6x + 18y + 26 = 0, is :
x2 + y2 - 4x - 6y - 12 = 0 and
x2 + y2 + 6x + 18y + 26 = 0, is :
Options
A.3
B.4
C.1
D.2
Solution
distance between centres (c1c2) = 13 r1 =
= 5 & r2 = 
= 8 c1c2 = r1 + r2 is a case of external touching (as shown in above figure), so three common tangents can be drawn.Create a free account to view solution
View Solution FreeMore Circle Questions
The length of the common chord of the circle x2 + y2 + 4x + 6y + 4 = 0 and x2 + y2 + 6x + 4y + 4 = 0 is-...The straight line (x − 2) + (y + 3) = 0 cuts the circle (x − 2)2 + (y − 3)2 = 11 at-...Find the co-ordinates of a point p on line x + y = _ 13, nearest to the circle x2 + y2 + 4x + 6y _ 5 = 0...The equation of the tangents from the origin to the circle x2 + y2 + 2rx + 2hy + h2 = 0, are...The equation of the circle which passes through (1, 0) and (0, 1) and has its radius as small as possible, is -...