RSUM for the Texas Instruments TI 85:

To enter the program, select 'PRGM', 'NEW'. When 'Name =' appears, type in 'RSUM', thenpress the 'ENTER' key. When you have finished typing in the program, press '2nd QUIT'. To run the program, select 'PGRM', 'EXEC', with'SLOPEFIE' highlighted.

PLEASE NOTE: '>' and '<' can be entered from the 'TEST' menu; '' can be entered by pressing the 'STO>' key; andall other function names, text, label and variable names are typed in from 'ALPHA' mode.Everything else is entered as a single keystroke on the calculator (for example, '+' isentered by pressing the '+' key).


Check: To use the program to approximate the value of , first let  y1 = x3in graph mode, then start the program. At the prompts, respond X-MIN: 1, X-MAX: 3, NO. OFSUBS: 100. The calculator will then approximate by using 100 sub-intervals ('subs'), and should produce the output:

Notice that the integrand must always be entered into y1 ingraph mode, and the variable of integration must always be x.

Please Note: This program is provided as a service, since the MathematicsDepartment neither recommends nor supports the TI 85. Because there are at least twosignificantly different versions of the TI 85, it is possible that the program listed heremight not work properly on some TI 85s.

(jac) Lastrevised: December 03, 1998