Question 444437
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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+5)^2/11+ (y+1)^2/36 = 1}}}  f = sqrt(36-11) = sqrt(25) = 5
  Center(-5,-1) and foci are (-5, -6) and (-5,4)
{{{drawing(300,300, -10,10,-10,10,  arc(-5,-1,6.6,12),
 grid(1),
circle(-5, -1,0.4),
circle(-5, -6,0.4),
circle(-5, 4,0.4),
graph( 300, 300,-10,10,-10,10))}}}