NTA Abhyas JEE Main2020MathematicsEllipsePractice
If x 2 + y 2 = a 2 and x 2 16 + y 2 9 = 1 intersect at 4 points P , Q , R and S which form a square, then the area (in sq. units) of the square is
Options
- A144 25
- B25 4
- C15 2
- D576 25
Correct answer
D. 576 25
Step-by-step solution
Let, P = a cos θ , a sin θ Then, a cos θ , a sin θ lies on x 2 16 + y 2 9 = 1 Also, θ = 45 ° because P , Q , R , S form a square ⇒ a 2 2 × 16 + a 2 2 × 9 = 1 ⇒ a 2 2 16 + 9 16 × 9 = 1 ⇒ a 2 = 2 × 144 25 ⇒ a = 12 2 5 ⇒ P Q = 24 5 Hence, the area of the square = 576 25