Question

Which is right? Please help.

Answer 1

Answer:

B  Graph B and D are functions

Step-by-step explanation:

To be a function, it has to pass the vertical line test.  The vertical line test says that if you move a vertical line over  the graph, it can only touch the graph once at any one time to be a function.

Graph A fails the vertical line test.

Graph B passes the vertical line test

Graph C fails the vertical line test

Graph D passes the vertical line test

Answer 2

A function is a relation that associates each element x of a set X to a single element y of another set Y.

For one x is one y.

Look at the picture.

Graph A: for x = 2 are two values of y.

Graph C: for x = 1 are two values of y.

Graph B and D: for each value of x is one value of y.

Answer: B. Graph B and graph D.