Let A={(α,β)∈R×R:∣α−1∣≤4 and ∣β−5∣≤6} and B={(α,β)∈R×R:16(α−2)2+9(β−6)2≤144}. Then
(A)B⊂A✓ Correct
(B)A∪B={(x,y):−4≤x≤4,−1≤y≤11}
(C)neither A⊂B nor B⊂A
(D)A⊂B
Answer: (A)
Solution
The conditions ∣x−1∣≤4 and ∣y−5∣≤6 describe set A as the rectangle −3≤x≤5,−1≤y≤11. The condition 16(x−2)2+9(y−6)2≤144 rewrites as 9(x−2)2+16(y−6)2≤1, an ellipse centred at (2,6) with horizontal semi-axis 3 and vertical semi-axis 4. Hence set B lies within −1≤x≤5 and 2≤y≤10. Both ranges sit inside the rectangle, and since the ellipse is contained in its bounding box, every point of B belongs to A. Thus B⊂A.
JEE Main · 2025 · 07 Apr 2025 · Shift 2 · Single correct option