The equations to the common tangents of the circles
and
are
Text Solution
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Both circles are non-intersecting.
Hence there are four common tangents.
Transverse common tangents :
coordinate of P
≡ 

Let slope of these tangents is m
y –
= m(x – 0) ⇒ mx – y +
= 0
Now
= 1 ⇒
= 
⇒ m 2 +
– m = 1 + m 2 ⇒ m = –
, other tangents is vertical
Equation of tangents x = 0
–
x – y +
= 0 ⇒ –3x – 4y + 10 = 0 ⇒ 3x + 3y = 10
Direct common tangents
coordinate of Q
≡ Q(3, 4)
Hence equations y – 4 = m(x – 3) ⇒ mx – y + (4 – 3m) = 0
⇒
= 1 ⇒ |1 – 2m| =
⇒ 1 + 4m 2 – 4m = 1 + m 2 ⇒ 3m 2 – 4m = 0 ⇒ m = 0, 
Hence equation y – 4 = 0(x – 3) ⇒ y = 4 ⇒ y – 4 =
(x – 3) ⇒ 4x – 3y = 0
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