write the equation of the ellipse in standard form having the given properties.
center(4,6) vertex(9,6)(0,8) is on the ellipse
Plot those points
Sketch in the ellipse approximately:
Since the ellipse is wider than it is tall, it has the
standard equation
= 1
And since the center is (h,k) = (4,6), we have
= 1
Now we draw in the semi-major axis, which connects the
center to the vertex:
We can observe that the semi-major axis is 5 units long, so
we know that a = 5, so we can substitute that and our
equation so far is:
= 1
or
= 1
Now since we know that the ellipse contains the point
(x,y) = (0,8), we substitute
= 1
= 1
= 1
Clear of fractions by multiplying through by LCD =
Since b is the length of the semi-minor axis,
we can now draw in the semi-minor axis 10/3 or
3 units long, which goes from the
center up to the ellipse:
To draw the ellipse more accurately we can now sketch
in the complete major and minor axes:
To finish the equation, we substitute for
= 1
and that is the desired equation in standard form.
Edwin