Find the center, vertices, and foci of the ellipse with equation 2x2 + 8y2 = 16.
Solution:
Given, the equation of the ellipse is 2x2 + 8y2 = 16 --- (1)
An ellipse is the locus of points in a plane, the sum of whose distances from two fixed points is a constant value.
The two fixed points are called the foci of the ellipse.
The standard equation of an ellipse is
\(\frac{(x-h)^{2}}{a^{2}}+\frac{(y-k)^{2}}{b^{2}}=1\) --- (2)
Where, the length of major axis is 2a
The coordinates of the vertices are (h ± a, k)
The length of the minor axis is 2b
The coordinates of the co-vertices are (h, k ± b)
The coordinates of the foci are (h ± c, k)
Where, c2 = a2 - b2
Dividing equation (1) by 16,
\(\frac{2x^{2}}{16}+\frac{8y^{2}}{16}=\frac{16}{16}\)
\(\frac{x^{2}}{8}+\frac{y^{2}}{2}=1\) --- (3)
Comparing (2) and (3),
h = 0 and k = 0
Therefore, centre (h, k) is (0, 0)
a2 = 8
So, a = 2√2
b2 = 2
So, b = √2
Vertices = (h ± a, k)
Vertices = (0 ± a, 0)
Vertices = (±a, 0)
Vertices = (±2√2, 0)
Vertices are (-2√2, 0) and (2√2, 0).
To find the value of c,
c2 = (2√2)2 - (√2)2
c2 = 8 - 2
c2 = 6
Taking square root,
c = √6
Foci = (h ± c, k)
= (0 ± c, 0)
= (±√6, 0)
Foci are at (-√6, 0) and (√6, 0).
Therefore, the center, vertices, and foci are (0, 0), (±2√2, 0) and (±√6 0).
Find the center, vertices, and foci of the ellipse with equation 2x2 + 8y2 = 16.
Summary:
The center, vertices, and foci of the ellipse with equation 2x2 + 8y2 = 16 are (0, 0), (±2√2, 0) and (±√6 0).
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