Question 475747
  <pre><font face = "Tohoma" size = 4 color = "indigo"><b> 
Hi,
{{{x^2 + 9y^2 = 81}}}
{{{x^2/81 + y^2/9 = 1}}}
 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.

{{{drawing(300,300,  -10,10,-10,10,   arc(0,0,18,6),
 grid(1),
circle(0, 0,0.4),
circle(9, 0,0.4),
circle(-9, 0,0.4),
circle(0, 3,0.4),
circle(0, -3,0.4),
graph( 300, 300, -10,10,-10,10))}}}