Question 848107
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Hi
major axis: a = 4
(3,0)and (-3,0);    and 6/2 = 3, foci distance from center 
 {{{9= 16 -b^2}}}  b^2 = 7
{{{(x)^2/16 + y ^2/7= 1}}} 
{{{drawing(300,300,  -10,10,-10,10,   arc(0,0,8,5.29),
 grid(1),
circle(3, 0,0.4),
circle(-3, 0,0.4),
graph( 300, 300, -10,10,-10,10))}}}
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