Question 629936
  <pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi,
ellipse with C(0,0), a vertical minor axis of length 6, and a horizontal major axis of length 10
  {{{x^2/5^2 + y^2/3^2 = 1}}}   {{{F[D] = sqrt(25-9) = sqrt(16) = 4}}}
 Standard Form of an Equation of an Ellipse is {{{(x-h)^2/a^2 + (y-k)^2/b^2 = 1 }}} 
where Pt(h,k) is the center. (a variable positioned to correspond with major axis)
 a and b  are the respective vertices distances from center
 and ±{{{sqrt(a^2-b^2)}}}are the foci distances from center: a > b
{{{drawing(300,300,   -10,10,-10,10,  arc(0,0,10,6),
 grid(1),
circle(4, 0,0.4),
circle(-4, 0,0.4),
graph( 300, 300, -10,10,-10,10))}}}