Question 451433
  <pre><font face = "Tohoma" size = 4 color = "indigo"><b> 
Hi, Assuming the vertices are (0,-4)and (0,4)
Note: Standard Form of an Equation of an Hyperbola opening up and down is:
  {{{(y-k)^2/b^2 - (x-h)^2/a^2 = 1}}} 
where Pt(h,k) is a center  with vertices 'b' units up and down from center.
Hyperbola with vertices are (0,-4)and (0,4)and foci at (0,7) and (0,-7)
{{{(y)^2/16 -(x)^2/a^2 =1}}}  C(0,0) with vertices V(0,-4) and V(0,4)
foci (0,-7) and(0,7)  c = sqrt(16 + a^2)= 7   a^2 = 33
{{{(y)^2/16 -(x)^2/33 =1}}}
{{{drawing(300,300,-10,10,-10,10,  grid(1),
circle(0, 0,0.3),
circle(0, -4,0.3),
circle(0, 4,0.3),
graph(300,300,-10,10,-10,10,0,4sqrt(1+ (1/33)(x)^2),-4sqrt(1+ (1/33)(x)^2)))}}}