
Bradford T. answered 08/20/21
Retired Engineer / Upper level math instructor
y = a(x-h)2+ k --> Vertex = (h,k)
y=a(x-4)2+3
Setting x to -x makes the parabola symmetric with the y-axis. Subtracting 5 moves the parabola down 5 units.
g(x) = f(x)-5 = a(-x-4)2+3-5 = a(-1)2(x+4)2-2 = a(x+4)-2
Which places the vertex of g(x) at (-4,-2).
The value of "a" stretches or shrinks the parabola, but doesn't change the vertex.