Hi
Note: the vertex form of a Parabola opening up(a>0) or down(a<0),
where(h,k) is the vertex and x = h is the Line of Symmetry.
y=x^2-2x-8 0r Completing the Square
y =x^2-2x +1 -1 -8
y =(x-1)^2-9 V(1, -9) and x = 1 is the Line of Symmetry
the coordinates of two other points on the curve:
P(0, -8) & P(-2, 0)
y=x^2-6x - 9 0r Completing the Square
y =x^2-6x+9 -9 -9
y =(x-3)^2-18 C(3, -18) and x = 3 is the Line of Symmetry
the coordinates of two other points on the curve:
P(2, -17) & P(1, -14)
Wish You the Best in your Studies.