First slide

Analysis of two circles in circles

Question

If $P (1, 1 / 2)$ is a centre of similitude for the circles $x^{2} + y^{2} + 4 x + 2 y - 4 = 0$ and $x^{2} + y^{2} - 4 x - 2 y + 4 = 0$ , then the length of the common tangent through P to the circles, i

Moderate

A

4
B

3
C

2
D

1

Solution

Clearly, $P (1, 1 I 2)$ is the internal centre of similitude. Thus, if PT₁ fi and PT₂ are the lengths of tangents drawn from P to the given circles, then Length of the common tangent $= P T_{1} + P T_{2} = \frac{3}{2} + \frac{1}{2} = 2$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App