AP EAPCET 24-Aug-2021 Shift 1 Paper

C1:x2+y2−8x−6y+21=0
C2:x2+y2−2x−15=0
Equation of circle passing through the point of intersection.
S1+λS2=0 Now, equation of circle passing through (1,2) is ⇒(1+4−8−12+21)+λ(5−2−15)=0
⇒6+λ(−14=0
⇒λ=

1

2

∴ Equation of required circle is ⇒3x2+3y2−18x−12y+42−15=0
,⇒3(x2+y2−6x−4y+9)=0
∴x2+y2−6x−4y+9=0