This is an investigation that I use to introduce the big ideas of inverse functions. Students graph a linear function by making a table of values, interchange the x & y values in a table of values and graph the resulting function. When students fold the graph along the line y = x they can see that the two graphs are symmetric. The tactile activity is something that students will refer back to as they study more complicated inverse functions. After graphing the investigation leads the students to look at the composition of the two functions, showing that f(g(x)) = x and g(f(x)) = x.