In this image, the task is to identify which graphs represent $y$ as a function of $x$. For $y$ to be a function of $x$, each value of $x$ must correspond to exactly one value of $y$. This means the graph must pass the vertical line test, where no vertical line intersects the graph at more than one point.

Let's analyze each option based on this criterion:

1. Graph A: The curve does not pass the vertical line test. A vertical line would intersect the curve at more than one point. Hence, A is not a function.

2. Graph B: The rays in the graph spread outwards and pass the vertical line test, as each vertical line touches the graph at exactly one point. B is a function.

3. Graph C: The graph has a curve similar to a sine wave, and it does not pass the vertical line test, as some vertical lines would intersect the graph at more than one point. C is not a function.

4. Graph F: This is a parabola opening downward, and it passes the vertical line test, as each vertical line intersects the graph at only one point. F is a function.

Therefore, the graphs that represent $y$ as a function of $x$ are B and F.

Do you want more details or have any questions?

Here are 5 related questions:

1. What is the vertical line test, and how does it work?
2. Why does a parabola always represent a function?
3. What kind of graph represents a non-function, and why?
4. Can multiple types of curves be functions, or are there restrictions?
5. How do we distinguish between one-to-one functions and many-to-one functions?

Tip: Always use the vertical line test to quickly determine if a graph represents a function!