Question 421906
  <pre><font face = "Tohoma" size = 4 color = "indigo"><b>
Hi
equation of an ellipse with foci at (1, -1) and (1, -7) and major axis of 10
C(1,-4)  b = 5 and f = 3   {{{sqrt(25-16) = 3}}}  a = 4
 {{{(y+4)^2/25 + (x -1)^2/16 =1 
{{{drawing(300,300,   -10,10,-10,10,  arc(1,-4,8,10),
 grid(1),blue(line(1,1,1,-9)) ,

circle(1, -4,0.4),
circle(1, -1,0.4),
circle(1, -7,0.4),
graph( 300, 300, -10,10,-10,10))}}}
{{{drawing(300,300, -10,10,-10,10, arc(1,-4,8,10),
 grid(1),blue(line(1,1,1,-9)) ,
circle(1, -4,0.4),
circle(1, -1,0.4),
circle(1, -7,0.4),
graph( 300, 300, -10,10,-10,10))}}}