For:
      vertex: (h, k)
      focus: (x1, y1)

• The Parobola Equation in Vertex Form is:
     (X-h)² = 4a(Y-k);    ( a = √(h-x1) * (h-x1) + (k - y1) * (k-y1) )

• The Parobola Equation in Standard Form is:
     Y = (1/4a)X² - (h/2a)X + (k + h²/4a);    ( a = √(h-x1) * (h-x1) + (k - y1) * (k-y1) )