Answer: See the graph attached.
Step-by-step explanation:
 The standard form of a quadratic function is:
 
 Where (h,k) is the vertex of the parabola.
 If  is negative, then the parabola opens down.
 is negative, then the parabola opens down.
 Then, for the function:
 
 You can identify:
 
 Then the  vertex of the parabola is at (2,4)
 Note that  , therefore the parabola opens down.
, therefore the parabola opens down.
 Find the intersection with the x-axis. Substitute  and solve for x:
 and solve for x:
 
 Knowing that the vertex is at (2,4), the parabola opens down and it intersects the x-axis at x=0 and x=4, you can graph the function, as you observe in the figure attached.