JEE Main202529 Jan 2025Morning ShiftMathematicsParabolaActual
Two parabolas have the same focus ((4,3) ) and their directrices are the (x )-axis and the (y )-axis, respectively. If these parabolas intersects at the points (A ) and (B ), then ((A B)^2 ) is equal to :
Options
- A392
- B384
- C192
- D96
Correct answer
C. 192
Step-by-step solution
The parabolas are (x-4)^2+(y-3)^2=x^2 ...(i) and (x-4)^2+(y-3)^2=y^2 ... If point of intersection are A (x₁, y₁ ) and B (x₂, y₂ ) By solving (i) and (ii), we get aligned & x₁+x₂=14 and x₁ x₂=25 & (A B)^2=2 ( (x₁+x₂ )^2-4 x₁ x₂ )=192 aligned