Answer:
1.Because the domain refers to the set of possible input values,the domain of a graph consists of all the input values shown on the x-axis.The range is the set of possible output values,which are shown on the y-axis
2.Use the vertical line test to determine whether or not a graph represents a function.If a vertical line is moved across the graph and,at anytime,touches the graph at only one point,then the graph is a function.If the vertical line touches the graph at more than one point,then the graph is not a function.