JEE Main2014MathematicsStraight LinesActual
Let P S be the median of the triangle with vertices P ( 2 , 2 ) , Q ( 6 , - 1 ) and R ( 7 , 3 ) . The equation of the line passing through ( 1 , - 1 ) and parallel to P S is
Options
- A4 x + 7 y + 3 = 0
- B2 x - 9 y - 11 = 0
- C4 x - 7 y - 11 = 0
- D2 x + 9 y + 7 = 0
Correct answer
D. 2 x + 9 y + 7 = 0
Step-by-step solution
P ( 2 , 2 ) ;   Q ( 6 , - 1 ) ;   R ( 7 , 3 ) S is the midpoint of Q and R . ∴    S ≡ 13 2 ,   1 ∴  Slope of P S = 2 - 1 2 - 13 2 = 1 - 9 2 = - 2 9 Therefore, the equation of the line passing through ( 1 , - 1 ) and parallel to   P S is y +1= - 2 9 x - 1 ∴  9 y +9=-2 x +2 ∴   2 x +9 y +7=0