Question 401170
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Hi
Standard Form of an Equation of an Hyperbola is  {{{(x-h)^2/a^2 - (y-k)^2/b^2 = 1}}} where Pt(h,k) is a center,  
and the vertices are 'a' units right and left of center.
(x+2)^2/81 - (y+4)^2/4 = 1   | a = 9 for this hyperbola
Center is Pt(-2,-4), therefore the vertices would be (-11,-4)  and (7,-4)
Foci: c = sqrt(a^2 + b^2)}}} {{{sqrt(81 + 4)}}} = sqrt(85)= 9.22
Pt(-11.22, -4) and Pt(7.22, -4)

<img src="http://upload.wikimedia.org/wikipedia/commons/thumb/9/97/Hyperbola_properties.svg/200px-Hyperbola_properties.svg.png">