AP EAMCET202119 Aug 2021Morning ShiftMathematicsCircleActual
The point which has the same power with respect to each of the circles x 2 + y 2 - 8 x + 40 = 0 , x 2 + y 2 - 5 x + 16 = 0 and x 2 + y 2 - 8 x + 16 y + 160 = 0 is
Options
- A− 8 , − 15 2
- B8 , − 15 2
- C8 , 15 2
- D− 8 , 15 2
Correct answer
B. 8 , − 15 2
Step-by-step solution
Given circle equations x 2 + y 2 - 8 x + 40 = 0 - - - ( I ) x 2 + y 2 - 5 x + 16 = 0 - - - - ( I I ) x 2 + y 2 - 8 x + 16 y + 160 = 0 - - - - I I I Power of point with respect to circle = S 1 For point P 8 ,   - 15 2 With respect to equation I = 64 + 225 4 - 64 + 40 = 385 4 With respect to equation I I =   64 + 225 4 - 40 + 16 = 385 4 With respect to third circle = 385 4 The remaining points in other options are not having same power. So required point is 8 ,   - 15 2 .