1. The problem statement, all variables and given/known data I'm reading through the help files and came across this example: s = tf('s'); H = s/(s^2 + 2*s +10); I understand that when using a rational expression it must be specified, s= tf('s'); I also understand that the rational expression is entered through H=s/(s^2 + 2*s +10); I'm just struggling a bit with how these two expressions connect to each other. To me it looks like s/(s^2 + 2*s +10) is being saved as H, but there is no H in the first expression. Is H arbitrary? Could s/(s^2 + 2*s +10) be saved under any name or is there significance in the letter H?