JEE Main201910 Jan 2019Evening ShiftMathematicsStraight LinesActual
Two sides of a parallelogram are along the lines, x + y = 3 and x - y + 3 = 0 . If its diagonals intersect at 2 , 4 , then one of its vertex is:
Options
- A3 , 6
- B2 , 6
- C2 , 1
- D3 , 5
Correct answer
A. 3 , 6
Step-by-step solution
As B C ∥ A D ⇒ Slope B C = Slope A D Hence, slope of B C = 1 ⇒ 3 - h - 5 h - 4 = 1 ⇒ - h - 2 = h - 4 ⇒   2 h = 2 ⇒ h = 1 ∴   B 1 , 2 and D 3 , 6