allerySum of distances from any point on ellipse 9x² + 16y² = 144 to its foci:
ACannot determine
B8 (= 2a, where a² = 16 → a = 4)
C6
D12
Answer & Solution
Correct answer: B. 8 (= 2a, where a² = 16 → a = 4)
x²/16 + y²/9 = 1. a² = 16, a = 4. Sum of focal distances = 2a = 8. (Definition of ellipse: 2a = constant.)
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