Question

Difficulty: EasyConic Sections

An ellipse in the standard (x,y)(x, y) coordinate plane is defined by the equation

(x2)29+(y+5)216=1\frac{(x-2)^2}{9} + \frac{(y+5)^2}{16} = 1

What are the coordinates of the center of this ellipse?

  1. A
    (2,5)(-2, 5)
  2. B
    (2,5)(2, 5)
  3. (2,5)(2, -5)Answer
  4. D
    (2,5)(-2, -5)
  5. E
    (5,2)(-5, 2)

Answer

The center of the ellipse is (2,5)(2, -5).
The standard form of an ellipse equation is (xh)2a2+(yk)2b2=1\frac{(x-h)^2}{a^2} + \frac{(y-k)^2}{b^2} = 1, where the center of the ellipse is at the coordinate point (h,k)(h, k). Comparing the given equation (x2)29+(y+5)216=1\frac{(x-2)^2}{9} + \frac{(y+5)^2}{16} = 1 to the standard form reveals that h=2h = 2 and k=5k = -5. Therefore, the center coordinates are (2,5)(2, -5).

Step-by-Step Solution

1
Recall the standard form equation of an ellipse with horizontal/vertical axes.
The standard form is (xh)2a2+(yk)2b2=1\frac{(x-h)^2}{a^2} + \frac{(y-k)^2}{b^2} = 1, where (h,k)(h, k) represents the coordinates of the center.
This establishes the framework to extract the center coordinate values.
2
Compare the terms in the given equation to the standard form.
Matching (xh)2(x-h)^2 with (x2)2(x-2)^2 gives h=2h = 2. Matching (yk)2(y-k)^2 with (y+5)2=(y(5))2(y+5)^2 = (y-(-5))^2 gives k=5k = -5.
Comparing terms identifies the offsets hh and kk that determine the center.
3
Write the center coordinate pair (h,k)(h, k).
The center is (2,5)(2, -5).
Combining the values of hh and kk yields the final coordinates.

Key Concept

Identifying the center of an ellipse from its standard form equation
Estimated Time:45s
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