What is the vertical line that divides the parabola into two equal part?

It would be the y-axis.

Step-by-step explanation:

the answer is b.)

< 1=< 2

look at the picture.

y-intercept for the function on a picture is 4 → point (0, 4).

y-intercept for the function

is for x = 0. substitute:

y-intercept is 8 → point (0, 8).