Question 430947
  <pre><font face = "Tohoma" size = 4 color = "indigo"><b> 
Hi
 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 and a and b  are the respective vertices distances from center.
(x-1)^2/25 + (y+2)^2/16 = 1     | a = 5 and b = 4  C(1,-2)
 f = sqrt(25-16) = 3  (foci are located 3 each side of center along major axis)  
 |foci are (-2,-2) and (4,-2)
{{{drawing(300,300,   -10,10,-10,10,  arc(1,-2,10,8),
 grid(1),
circle(1, -2,0.4),
circle(-2, -2,0.4),
circle(4, -2,0.4),
green(line(-4,-2,6,-2)),
graph( 300, 300, -10,10,-10,10))}}}