Question 927237
{{{x^2/a^2 + y^2/b^2 = 1}}}
.....points [3, sqrt(7)] and [-sqrt(3), 3]
9/a^2 + 7/b^2 = 1
<u>-3(3/a^2 + 9b^2 = 1)</u>
-20/b^2) = -2
b^2 = 10
.......  
9/a^2 + 7/10 = 1
9/a^2 = 3/10
a^2 = 30
.........
{{{x^2/30 + y^2/10 = 1}}}

{{{drawing(300,300,   -6, 6, -6, 6, grid(1), arc(0,0,2sqrt(30),2sqrt(10)), 
circle(3, sqrt(7),0.3),
circle(-sqrt(3), 3, 0.3),
circle(0,0, 0.3),
graph( 300, 300, -6, 6, -6, 6,0) )}}}