Question:medium

The eccentricity of the ellipse represented by the equation \(7x^2+16y^2-14x+64y-377 = 0\) is...

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Complete the squares to reach standard form, then use e squared = 1 - b squared / a squared.
Updated On: Oct 1, 2026
  • \(\frac{3}{4}\)
  • \(\frac{\sqrt{7}}{4}\)
  • \(\frac{1}{2}\)
  • \(\frac{3}{8}\)
Show Solution

The Correct Option is A

Solution and Explanation

Step 1: Shift the origin
Move to $X = x - 1$, $Y = y + 2$. The equation becomes $7X^2 + 16Y^2 = 448$.

Step 2: Semi-axes
$a^2 = \frac{448}{7} = 64$ and $b^2 = \frac{448}{16} = 28$. Since $a^2 > b^2$, $a = 8$ is the semi-major axis.

Step 3: Focal distance
$c^2 = a^2 - b^2 = 36$, so $c = 6$ and $e = \frac{c}{a} = \frac{6}{8}$.

Step 4: Result
$e = \frac{3}{4}$. The value $\frac{\sqrt{7}}{4}$ equals $b/a$ for this ellipse, not $e$.

Final Answer:
The eccentricity is 3/4. This is option (A). \[ \boxed{\text{(A) }\frac{3}{4}} \]
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