This applet allows you to investigate domain and range of linear functions [math]f(x)=mx+b[/math]. To change the slope [math]m[/math] and y-intercept [math]b[/math], slowly drag the appropriate slider. To visualize the domain, slowly drag the "d" slider. To visualize the range, slowly drag the "r" slider. To see both domain and range simultaneously, check the box.