Consider we need to find the equation of ellipse.
Given:
Ellipse is centered at the origin.
Major axis is horizontal, with length 8.
The length of its minor axis is 4.
To find:
The equation of ellipse.
Solution:
Major axis is horizontal, so standard form of ellipse is
...(i)
where, (h,k) is center of the ellipse and length of major axis is 2a and length of minor axis is 2b.
Ellipse is centered at the origin. So, h=0 and k=0.
Major axis is horizontal, with length 8.


The length of its minor axis is 4.


Substitute h=0, k=0, a=4 and b=2 in equation (i).


Therefore, the required equation of ellipse is
.