To solve this problem you must apply the proccedure shown below:
1. You have that the equation of the ellipse is the following:
(x²/400)+(y²/256)=1
2. You have that:
((x-0)²/400)+((y-0)²/256)=1
3. Then, the center is:
(0,0)
4. The vertices are:
a²=400
a=√400
a=20
(-20,0)
(20,0)
b²=256
b=√256
b=16
(0,-16)
(0,16)
5. The focci is:
a²–c²=b²
√(400-256)=c
c=12
(-12,0)
(12,0)
