How can we determine from a graph if a function is shown or not?
To determine if a function is represented on a graph, you need to check if the graph passes the vertical line test. The vertical line test states that if any vertical line intersects the graph at more than one point, then the graph does not represent a function. If every vertical line intersects the graph at most at one point, then it represents a function.
To apply the vertical line test, imagine drawing vertical lines at various positions on the graph and observe how they intersect with the graph. If any vertical line intersects the graph at multiple points, then the graph does not represent a function. If every vertical line intersects the graph at most at one point, then the graph represents a function.