Trapezoid Summation

So, this program is useful if you are in "Advanced Math" or "Pre-Calculus", but it's not really useful anywhere else. Anyway, let's get right into it:

1. Create a new program and name it TRAPSUM (or something that you will remember it by)

2. Press prgm, go to the I/O tab, and select ClrHome. Start a new line by pressing enter

3. Press prgm, go to the I/O tab, and select Input

4. Type out "EXPRESSION: " and press comma

5. Press vars, go to String, and select Str1. Start a new line

6. Repeat step 3 and type "START: "

7. Press comma, type S, and start a new line

8. Repeat step 3 and type "END: "

9. Press comma, type E, and start a new line

10. Repeat step 3 and type "INTERVALS: "

11. Press comma, type I, and start a new line

12. Get Str1 again, then press sto→

13. Press vars, go to the Y-VARS tab, select Function, and select Y₁. Start a new line

14. Type (E-S)/I→N and start a new line

15. Type E-N→O and start a new line

16. Type S+N→P and start a new line

17. Type N, then press 2nd stat, go to the MATH tab, and select sum(

18. Press 2nd stat, go to the OPS tab, and select seq(

19. Get Y₁ again and press comma,

20. Type X,S,O,N))→L and start a new line

21. Repeat steps 17-19 and type X,P,E,N))→R

22. Type (L+R)/2→T

23. Press prgm, go to the I/O tab, and select Disp, then type "LEFT:",L

24. Press prgm, go to the I/O tab, and select Disp, then type "RIGHT:",R

25. Press prgm, go to the I/O tab, and select Disp, then type "TRAP:",T

26. Your program should look like:

:ClrHome

:Input "EXPRESSION: ",Str1

:Input "START: ",S

:Input "END: ",E

:Input "INTERVALS: ",I

:Str1→Y₁

:(E-S)/I→N

:E-N→O

:S+N→P

:Nsum(seq(Y₁,X,S,O,N))→L

:Nsum(seq(Y₁,X,P,E,N))→R

:(L+R)/2→T

:Disp "LEFT:",L

:Disp "RIGHT:",R

:Disp "TRAP:",T

If you found this helpful give it a like. If you have any questions or need help, drop a comment. Thanks for taking the time to do some programming!

-Nate