SOLUTION Let y = f(x) or, y=x2−6x+9. The following table gives the values of y or f (x) for various values of x.
x
-2
-1
0
1
2
3
4
5
6
7
8
y=x2−6x+9
25
16
9
4
1
0
1
4
9
16
25
Thus, the graph of y=x2−6x+9 passes through the points (-2,25), (-1,16), (0,9), (1,4), (2,1),(3,0),(4,1),(5,4),(6,9),(7,16)and (8,25).Let us plot these points on the graph and draw a free hand smooth curve passing through these points. We observe that the vertex of the parabola is at point P (3,0) as shown in Figure.