Hi
f(x)= ax^2 + bx + c
f(x) = -x^2+2x+5 P(0,5) on this parabola
the vertex form of a Parabola opening up(a>0) or down(a<0),
f(x) = -x^2+2x+5
Completing the Square to Find Vertex Form
f(x) = -(x - 1)^2 + + 1 + 5 Note: h == 1
f(x) = -(x - 1)^2 + 6
parabola opening downward a = -1 < 0
P(0,5), V(1, 6) Line of symmetry, x = 1
f(x) = 0, x = 1 ± √6
Sketch