# Left Right Sums - TI 89 or TI 92

Introduction
This program computes left and right hand approximations for  .

If you have not used one of the programs posted on this website before, you should read through the information in the Intro to Programming section first.

If you have a TI Connectivity Cable, you can download the program main.lrsums.89p

The Program
 :lrsums( ) {This will already appear if you named the program lrsums} :Prgm {This will already appear} :Lbl p {Lbl is in the CATALOG menu} :Local a,b,n {Local is in the F4 menu} :Input "a=", a {Input is in the F3 menu} :Input "b=", b :Input "n=", n :(b-a)/nh :ax :0l {The 0 is a zero}{The l is a lowercase L} :0m {The 0 is a zero} :For j,1,n {The 1 is a one} :l+y1(x)*hl (The l is a lowercase L} {y1 is the Y button followed by a 1} :x+hx :EndFor {For EndFor is in the F2 menu} :l+y1(b)*hr {The l is a lowercase L} :r-y1(a)*hr :(l+r)/2t {The l is a lowercase L} :Disp "left", l {Disp is in the F3 menu} {l is a lowercase L} :Disp "right", r :Disp "average", t :Pause {Pause is in the CATALOG menu} :Goto p {Goto is in the CATALOG menu} :EndPrgm {This will already appear}

Running the Program

You will need to enter a function f(x) into y1 before running the program. The program will ask for values of A, B, and N (number of subdivisions).

To test the program try the following:
f(x)  =  x2+ 3,   A=1,   B=4,   N=20.

Your answer will be
left
28.88625
right
31.13625
average
30.01125