#### Answer

(a) In Figure 1 the graph is not a function of x.
(b) In Figure 2 the graph is a function of x

#### Work Step by Step

(a) The graph is not a function of x because there are vertical lines that intersect the curve twice. And we know that in order for it to be a function, each x must have a unique output, but in this case where the vertical line intersects twice, it indicates that the x value has two different y value outputs.
(b) Using the above information from part a, there is no vertical lines intersecting the graph more than once, hence each x value only has one y value output. Therefore this is a function.