The function f (x) = (x - 4) (x - 2) is shown. What is the range of the function? all real numbers less than or equal to 3 all real numbers less than or equal to - 1 all real numbers greater than or equal to 3 all real numbers greater than or equal to - 1

This parabola y=f (x) = (x²-6x+8) is:

1) Open downward (a>0)

2) it's axis of symmetry = - b/2a = 62 = 3

3) for x=3, y = - 1, So its minimum is at (3,-1)

4) Since its minimum is at y=-1, so it cannot go below - 1

5) So its range is {y∈R: y> = - 1}

or all real numbers greater than or equal to - 1