AP EAMCET202422 May 2024Morning ShiftMathematicsCircleActual
If A and B are the centres of similitude with respect to the circles x^2+y^2-14 x+6 y+33=0 and x^2+y^2+30 x-2 y+1=0 , then midpoint of AB is
Options
- A( 7 3 , 4 5 )
- B( 3 2 , 1 5 )
- C( 39 2 , -7 4 )
- D( 39 4 , -7 2 )
Correct answer
D. ( 39 4 , -7 2 )
Step-by-step solution
aligned & S₁ x^2+y^2-14 x+6 y+33=0 & C₁=(7,-3), r₁= 49+3-33 =5 & S₂ x^2+y^2+30 x-2 y+1=0 & C₂=(-15,1), r₂= 225+1-1 =15 aligned Let A divides C₁ C₂ in r₁: r₂ internally A= ( 21-15 4 , 1-9 4 )= ( 3 2 ,-2 ) Let B divides C₁ C₂ in r₁: r₂ externally B= ( -21-15 1-3 , 1+9 1-3 )=(18,-5) Midpoint of A B= ( 18+ 3 2 2 , -5-2 2 )= ( 39 4 , -7 2 )