Sum 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.)
Related questions
The Cassegrain telescope design uses the reflective property of a:A satellite dish uses a parabolic reflector because:By Kepler's First Law, every planet orbits the Sun in:For a general 2nd-degree equation Ax² + Bxy + Cy² + Dx + Ey + F = 0, the curve is a PARABOThe HYPERBOLA x²/a² − y²/b² = 1 has asymptotes given by:In the standard ellipse x²/a² + y²/b² = 1 (with a > b), the relationship between a, b, c (The standard form of a circle with centre (3, -2) and radius 5 is:The eccentricity of a CIRCLE is: