TI 81 Range Program This program is handy for graphs which you would like to trace. Usually when tracing, all of the values are long decimals. To alleviate this, the range of x should be a multiple of 19 (The one we are using is -28 to 29 with a scale of 3) and the range of y should be a multiple of 7 or 9 or both (we used -31 to 32, also with a scale of 3). This program automatically enters the range and scale values for you. prgm 6:Range :-28 -> Xmin :29 -> Xmax :3 -> Xscl :-31 -> Ymin :32 -> Ymax :3 -> Yscl :end Entering the program: Underlined words represent buttons to press # represents the cursor Keystrokes Screen PRGM cursor across to EDIT cursor down to next empty PRGM ENTER PRGM 6:# RANGE ENTER PRGM 6:RANGE :# -28 STO :-28 # VARS cursor over to rng select 1 (Xmin) ENTER :-28 -> Xmin 29 STO :-29 # VARS cursor over to rng select 2 (Xmax) ENTER :-28 -> Xmax 3 STO :3 # VARS cursor over to rng select 3 (Xscl) ENTER :3 -> Xscl -31 STO :-31 # VARS cursor over to rng select 4 (Ymin) ENTER :-31 -> Ymin 32 STO :32 # VARS cursor over to rng select 5 (Ymax) ENTER :32 -> Ymax 3 STO :3 # VARS cursor over to rng select 6 (Yscl) ENTER :3 -> Yscl :# PRGM cursor down to 7 ENTER :END To run the program just hit PRGM and cursor down to the range program and hit ENTER again twice. This will automatically make the next graph you display will be easily traceable.