JEE Main201911 Jan 2019Evening ShiftMathematicsStraight LinesActual
If in a parallelogram ABDC , the coordinates of A , B and C are respectively (1,2),(3,4) and (2,5), then the equation of the diagonal AD is :
Options
- A5 x-3 y+1=0
- B5 x+3 y-11=0
- C3 x-5 y+7=0
- D3 x+5 y-13=0
Correct answer
A. 5 x-3 y+1=0
Step-by-step solution
Since, in parallelogram mid points of both diagonals coinsides. mid-point of A D= mid-point of B C ( x₁+1 2 , y₁+2 2 )= ( 3+2 2 , 4+5 2 ) (x₁, y₁ )=(4,7) Then, equation of A D is, y-7= 2-7 1-4 (x-4)y-7= 5 3 (x-4)3 y-21=5 x-205 x-3 y+1=0