COMEDK2016MathematicsCircle
The equation of the common tangent of the two touching circles, y²+x²-6 x-12 y+37=0 and x²+y²-6 y+7=0 is
Options
- Ax+y+5=0
- Bx+y-5=0
- Cx-y+5=0
- Dx-y-5=0
Correct answer
D. x-y-5=0
Step-by-step solution
Let aligned S₁ & x²+y²-6 x-12 y+37=0 and S₂ & x²+y²-6 y+7=0 aligned The equation of common tangent of the two circles is aligned & S ₁- S ₂=0 & x²+y²-6 x-12 y+37- (x²+y²-6 y+7 )=0 & -6 x+6 y+30=0 & x-y-5=0 aligned