Hi
Standard Form of an Equation of an Ellipse is
where Pt(h,k) is the center with a and b determining the respective vertices distances from center.
x^2/9+y^2/16=1
Center(0,0) Vertices: (3,0),(-3,0) and (0,4),(0,4)
foci distance from center along major axis: 
foci: (0,sqrt(7)),(0,-sqrt(7))
