Find the length of the major axis of the ellipse 4x^2 + 9y^2 = 36.
Answer and explanation
Correct answer: D. 6
- Step 1: Divide by 36 to convert to standard form: (x^2 / 9) + (y^2 / 4) = 1.
- Step 2: Identify semi-major axis: a^2 = 9, so a = 3.
- Step 3: The length of the major axis is 2a = 2(3) = 6.
Answer
6.
Why not the others: '4' gives the length of the minor axis 2b = 2(2) = 4; '3' gives the semi-major axis a; '12' calculates 4a.
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