Answer
The required graph is as follows:
Work Step by Step
The given equation $y=x^2-6x+8$ is a parabola $(\cup-\text{shaped})$ curve. It has vertical symmetry about the minimum point.
The roots are the points where the y-coordinate is zero. Here, $x=2$ and $x=4$ are the points where $y=0$. Thus, the roots are $(2, 0)$ and $(4, 0)$.
The line of symmetry passes from the mid of the roots, i.e., $x=3$ is the line of symmetry. The minimum point lies on the line of symmetry, so, $y=(3)^2-6(3)+8=-1$, i.e., $(3, -1)$ is the minimum point.
Now, finally make a $\cup-\text{shaped}$ curve passing through roots and minimum point to obtain the graph as follows:
