Given the equation of an ellipse is 4x^2 + 16y^2 =
64.
We need to find the center and
foci.
First we need to re-write the equation into the
standard form of the ellipse.
==> x^2/a^2 + y^2 /
b^2 = 1..............(1)
==> 4x^2 + 16y^2 =
64.
Let us divide by 64
.
==> 4x^2/64 + 16y^2/64 =
1
==> x^2/ (64/4) + y^2/ (64/16) =
1
==> x^2 / (16) + y^2 / 4 =
1
==> x^2/ (4^2) + y^2 / (2^2) =
1............(2)
Comparing equation (1) and (2) we conclude
that:
a = +-4 and b=+- 2.
Then
the vertices's are:
(4,0) , (-4,0), ( 0,2)
and ( 0,-2).
==> Then
the center is (0, 0).
==> C^2 = a^2 -
b^2
==> C^2 = 16 - 4 =
12
==> c= +-sqrt12 =
+-2sqrt3
==> The foci is ( 2sqrt3,0 )
and (
-2sqrt3,0)
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