There are two circles whose equations are 
and 
. If the two circles have exactly two common tangents then the number of possible values of 
is
a)
2
b)
8
c)
9
d)
None of these
There are two circles whose equations are and . If the two circles have exactly two common tangents then the number of possible values of is
a)
2
b)
8
c)
9
d)
None of these
Question ID - 56691 | SaraNextGen Top Answer
There are two circles whose equations are and . If the two circles have exactly two common tangents then the number of possible values of is
a)
2
b)
8
c)
9
d)
None of these
|
There are two circles whose equations are |
|||||||
|
a) |
2 |
b) |
8 |
c) |
9 |
d) |
None of these |
1 Answer
127 votes
Answer Key / Explanation : (c) -
(c)
For 
, the centre 
and the radius 
For 
,
The centre 
and the radius 
or 
or 
Circles should cut to have exactly two common tangents
So, 
(distance between centres)
or 
or 
or 
Therefore, common values of 
should satisfy 
But 
. So, 
127 votes
Answer Link
127