Use the two sliders to change the appearance of the line. Watch how the slope value (m) affects the direction and steepness of the line. Adjust the value of b and see how the graph changes. Based upon the value of b and the location of the line, what should we call the value of b?

Draw a line with a slope of 1 and a b value of zero. (1) What angle does this line make with the x-axis? (2) How do the values of x and y compare at different points on the line? (3) Why do you think this is called the "identity function?"