関連ワード:  how can a graph represent a function    how to know a graph represents a function    how to tell a graph represents a function    how does a graph represent y as a function of x    how to know if a graph represent a function    how to determine if a graph represents a function    how to tell if a graph represents a function that has an inverse    how to know whether a graph represents a function    how to know if a graph represents a function or not    what does a graph that represents a function look like