Question

Which graph represents Y as a function of x?

Answer 1

Answer:

D

Step-by-step explanation:

a "function" gives every x value exactly one y value.

A, B and C all have 2 or more y values for an x value.

use e.g. a pen and place it vertically (straight top-down, parallel to the y-axis) on the graphs.

how often does the pen intersect the function curve ?

that is what I am talking about.

if it is more than once, than the x value (the point on the x-axis), where you put your pen, has more than 1 y values.

and that is then not a function.

only D is a function. the pen intersects with the function curve only once, no matter where you put the vertical pen.