AP EAMCET20224 Jul 2022Evening ShiftMathematicsStraight LinesActual
Suppose P and Q are the mid points of the sides A B and B C of a triangle where A 1 , 3 , B 3 , 7 and C 7 , 15 are vertices. Then the locus of R satisfying A C 2 + Q R 2 = P R 2 is
Options
- A6 x + 12 y = 297
- B6 x + 12 y + 297 = 0
- C12 x + 6 y = 297
- D12 x + 6 y + 297 = 0
Correct answer
A. 6 x + 12 y = 297
Step-by-step solution
Given, P and Q are the mid points of the sides A B and B C of a triangle where A 1 , 3 ,   B 3 , 7 and C 7 , 15 are vertices, So, coordinates of P are 3 + 1 2 , 7 + 3 2 = 2 , 5 and of Q are 3 + 7 2 , 7 + 15 2 = 5 , 11 . Let the coordinates of R be x , y , Then A C 2 + Q R 2 = P R 2 ⇒ P R 2 - Q R 2 = A C 2 ⇒ x - 2 2 + y - 5 2 - x - 5 2 + y - 11 2 = 7 - 1 2 + 15 - 3 2 ⇒ 6 x + 12 y + 4 - 121 = 36 + 144 ⇒ 6 x + 12 y = 297 which is the locus of R