Question 610137
  <pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi, 
Yes, Using the Vertex Form for a Parabola Opening Up and Down: y = a(x-h)^2 + k Does not work
Using the vertex form of a parabola opening right and left, {{{x=a(y-k)^2 +h}}} where(h,k) is the vertex
V(-2,4);P(3,-1) 
 x = a(y-4)^2 -2
3 = a(-5)^2 -2
 5/25 = a
 1/5 = a
{{{ x = (1/5)(y-4)^2 -2 }}},this is the Vertex form for parabola opening right and or left ( in this case {{{highlight(1/5)}}}>0, opens right.   
{{{drawing(300,300,   -6, 6, -6, 6, grid(1),
circle(-2, 4,0.3),
circle(3, -1,0.3),

graph( 300, 300, -6, 6, -6, 6,0,4, 4 + sqrt(5(2+x)), 4 -sqrt(5(2+x))))}}}