Stephen H. answered 01/13/21
Tutor of Math, Physics and Engineering ... available online
Vertex form = y-k=4p(x-h)2 where (h,k) = vertex. Replacing h & k with the given location of the vertex yields y-2=4P(x+2)2. Inserting the given point of (1,20) yields 20-2=4p(1+2)2. Solving, 4P=2 thus the vertex form of this parabola is y-2=2(x+2)2.

James M.
01/13/21