The equations of two circles are x2+y2+2λx+5=0 and x2+y2+2λy+5=0.P is any point on the line x−y=0. lf PA and PB are the lengths of the tangents from P to the two circles and PA=3 then PB=______
A
1.6
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
6
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
4
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
3
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution
The correct option is D3 s1:x2+y2+2λx+5=0
s2:x2+y2+2λy+5=0
So, eqn of radial axis of this circles is given by
s1−s2=0
⇒2λ(x−y)=0
x=y
So, length of tangents from any point on line x−y=0 are equal.