Brief Users Guide for the TI-83 Plus
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INDEX:

To facilitate lookup, the instructions are divided into the following categories:

I.   Basic Information - What's my operating system version?, how much RAM do my programs
take, is my calc upgradeable?, adjusting brightness of display, friendly values using TRACE.

II.  Basic Math – Math operations, how to change settings, and how to obtain certain symbols.
III.  Special Expressions – Absolute Value, Greatest Integer, etc.
IV.  Graphing and Evaluating Functions – Graphing, finding roots, finding intersections of graphs,
graphing inequalities, marking points on a graph, etc.
V.  Special Functions – Greatest Integer, Absolute Value, Piecewise Functions, Trig Functions,
etc.  Using [TABLE] to find points for graphing a parabola by hand.
VI.  Calculus – Finding the derivative at a certain point, finding the integral.
VII.  Matrices – Determinant, Transpose, Row Operations, solving a system of equations, source for program for rref and ref.
VIII.  Sequences - Finding several terms of a sequence, finding a specific term of a sequence,
summing sequences, cumulative sum of sequence.
IX.  Complex Numbers - Solving a polynomial with complex coefficients,  program for finding complex coefficients,

X.  Combining and Connecting Operations - Doing expressions with several terms,
X.  Transferring Programs and Data – Transferring data or programs from one calculator to
another.
XI.  Problems.

GENERAL:   All keys have at least two functions and some have three.  The default function for a key is the white print on the key.  When 2nd is pressed the key function is as indicated in yellow print (gray on some later models) on the panel immediately above the key.  When ALPHA is pressed, the function is the white label immediately above the key and, in most cases, near the right end of the key.  When APPS is pressed, the names of applications that your calculator has installed are displayed.

I.  BASIC INFORMATION

1.  Turning the calculator ON and OFF.
a)  To turn on: Press the ON key.
b)  To turn off:  Press 2nd; then OFF (the second function for the ON key.)

2.  Adjusting the contrast of the screen.
a) To make the screen display darker: Press the 2nd key; then press the arrow
key.
b) To make the screen display lighter: Press the 2nd key; then press the down
arrow key.

3.  Finding your operating system version number.
a)  Press 2nd; then MEM.  The memory management screen will be displayed.
b)  Press ENTER and a screen will be displayed with the version number of the OS.  It may be
anything from 1.12 to 1.18.
4.  Finding our how much free RAM I have.
a)  Press 2nd; then MEM. Scroll to 2: Mem Mgmt/Del...and press ENTER.
b)  The FREE RAM and ARC MEM (archive memory) will be displayed.
c)  To find out how your memory is used, for example how much memory a program used,
from the above screen, highlight 1:Real and press ENTER.

5.  Is my calculator upgradeable?  TI-83 Plus and later are upgradeable.  The TI-82 and TI-83 (not

6)  Friendly Values on Graphs Using TRACE:
Many times when you use the TRACE function, you will get an x-value such as 2.784532.  If you change the x-min and x-max
in the WINDOW function to be multiples of 4.7 and the y-min and y-max to multiples of 3.1, the displayed values will be "friendlier."
That is, they will be integers or numbers with one or two decimal places.  You can always set the values by hand, but the easiest
method is to use the ZDecimal function of ZOOM.  Just press ZOOM; then 4, for ZDecimal.
It may be that the display is now partially off the screen.  If you want the entire graph on the screen, use the Zoom Out function.
To do that, press ZOOM, 3, ENTER.   Incidentally, 4 seems to be the default setting for the zoom factors.  So, if your graph is
now too small, set the factors to 2 if they’re not already set at 2.  To do that press ZOOM, cursor to MEMORY, press 4, and
set both factors to 2.
If you’re trying to find the value at a specific point, a zero for example, and the cursor still does not fall on the x-axis, you could
try different strategies such as ZBox, but I usually prefer to use the zero function.  To do that, press 2nd, CALC, 2.  That will
set you up for finding a zero.  Remember that any time you want to get back to the standard window just press ZOOM, 6.

II. BASIC MATH
1. Clearing the Calculator Screen.
a) To clear the calculator screen: Press the CLEAR key.
b)  Note that CLEAR may also take you to another screen if you are using one of
the screens that does not permit data entry.

2.  To move to another screen:
a)  Press 2nd, QUIT.
b)  You can also use CLEAR if you’re not using a screen on which entries are made.  Some
examples of screens where entries are made are the following: Y=, List, or PRGM.

3. Correcting errors or changing characters.
a) To replace a character at the cursor position, just press the new
character.
b) To insert a character in the position of the cursor, press  2nd, press
the INS key, and then press the key for the desired character.
c) To delete a character in the position of the cursor, press the
DEL key.

4. Changing the MODE:
(Use the MODE for such things as changing from degrees to radians, displaying numbers as
powers of ten, using split screen, enabling complex number calculations and other
similar things.)
a) Press the MODE key.
b) Use the arrow keys to move the cursor to the desired item.
c) Press ENTER to highlight the selected item.
d) Press CLEAR or 2nd, QUIT to return to the home screen,

5. Performing numerical calculations,
a) On the graphing calculator screen, the multiplication symbol will appear
as * and the division symbol will appear as /.
b) Parentheses can be used to denote multiplication or as grouping symbols to
clarify the order of operations.
c) To enter an exponent use the ^ key for any exponent.  You can also use the x2
to raise a number to the second power. Other functions are available by pressing MATH.
d) Use the (-) key for negative numbers and the - key for subtraction.

6. Raising a number to a power:
a) Enter the number.
b) Press the ^ key
c) Enter the number for the power.
d) Press ENTER.
e) For an exponent of 2 only, you can use the x2 key after entering the
number that you want to raise to the second power.
f) Alternate method for raising to the third power only:  Enter your number,
press MATH; then 3; then ENTER. (Note that using ^ is more efficient.)

7. Finding the root of a number:
a)  For square root, press 2nd; then the square root symbol (x2 key).
b) For other roots, enter the number for the root index.
c) Press the MATH key.
d) Press 5 to paste the unspecified root symbol to the screen.
e) Enter the number you want to find the root of.
f)  Press ENTER.
g)  As an alternate method for cube root only, you can also choose to press
MATH, enter 4 to select item 4, and enter your number. Finally, press ENTER.

8.  Operations with fractions:
a)  Use the divide symbol between the numerator and denominator. Ex: ¼ is
entered as 1÷4.
b)  Use the correct operator symbol (divide, multiply, add, subtract) between
fractions.
c)  Pressing ENTER will give you the answer in decimal format.  To get the answer
as a fraction, skip step c) and continue as below.
d)  Press MATH to select Frac; then ENTER.
NOTE:  You can convert decimals to fractions using step d), but the decimal
must have 12 decimal places.  Example:  To convert the decimal equivalent of
1/3 to a fraction, you must enter this number, .333333333333.  Otherwise the
calculator will just return the decimal you entered.

III.  SPECIAL EXPRESSIONS:
1. To enter the symbols, equal to, not equal to, greater-than, less than, greater than or equal to, and less than or equal to:
a) Press the 2nd ; then the TEST key.
b) Enter the item number for the desired symbol.

2. To find the absolute value of a number:
a)   Press MATH and move the cursor to NUM.
b)  Press 1 to paste Abs( to the home screen.
d)  Press ENTER.

3. Finding the greatest integer function of a number.
a) Press the MATH key.
b) Use right arrow to move the highlight to NUM.
c) Press 5 to select lnt(.
e) Press ENTER. (Note that this also works for negative numbers.)

IV.  GRAPHING & EVALUATING FUNCTIONS:

(NOTE:  Always make sure that the Plot functions are not highlighted before graphing anything other
that statistical information.)
1. Graphing a function.
a) Press the Y= key.
b) Enter the function(s) using the [X,T,Θ,n] key to enter the variable.
c) Press GRAPH to graph the function.  (If you don’t see your graph, press
TRACE and use the arrows to find the maximum or minimum value of your
function.  Press ENTER.)
d) To leave the screen without graphing: press 2nd, QUIT.
e) Press CLEAR while the cursor is on the same line as the function to erase the
function.
f)  To deselect a function, move the cursor to the equal sign and press ENTER.

2.  To obtain the standard size viewing window:
a) Press the Zoom key.
b) Press 6 to execute Z Standard.

3.   To change the viewing window to a custom size:
a) Press the WINDOW key.
b) Use the cursor keys to move the cursor to the value to be changed.
c) Enter the new value.
d) Press Graph to see the new graph, or press 2nd, QUIT to return to the calculations
screen.
e) ZSquare keeps the y-scale the same and adjust the x-scale so that one unit
on the x-axis equals one unit on the y-axis.
f)  ZDecimal makes each movement of the cursor equivalent to one-tenth of a
unit.
g) ZInteger makes each movement of the cursor equivalent to one unit.

4.  Evaluating a function.
a) Press 2nd, Y-VARS.
b) Press ENTER.
c) Select the name of a function, e.g., Y1.
d) Enter an x-value as Y I (3) or a list of x-values in the form Y1 ({2,3,4,5}).  (In the
last form, make sure the interior grouping symbols are braces rather than
parentheses.)
e) Press Enter.
f)  As an alternative to this, see "Finding the value of a function at a given value of x," below.

5.  To change or erase a function:
a) Press the Y= key.
b) Use the arrow keys to move the cursor to the desired location and make
changes by inserting, deleting, or changing the desired characters.
c) To erase a function, with the cursor on the same line as the function, press the
CLEAR key.

6. To use the trace function:
a) Press the Trace key.
b) Use the right and left arrow keys to move the cursor along the graph. The
coordinates of the cursor location are shown at the bottom of the screen.
c) If more than one graph is on the screen, you can press the up or down arrows
to jump from one graph to another.

7.  Finding the maximum and minimum points.
a) Enter the function and graph.
b) Press the 2nd, CALC.
c) Press 3 for minimum or 4 for maximum.
d) Move the cursor to the left of the point and press ENTER.
e) Move the cursor to the right of the point and press ENTER
f)   Move the cursor slightly between those two points and press ENTER again.
g) The maxima or minima will appear at the bottom of the screen.

8.  Finding the value of a function at a given value of x.
a) Enter the function and the graph.
b) Press the Calc key.
c) Press 1 to select value.
d) Enter the x-value and press ENTER. The y-value will appear at the bottom of the screen

9.  To zoom in using a box.
a) Enter the function and graph.
b) Press the ZOOM key.
c) Press 1 to select ZBox.
d) Move the cursor above and to the left of the location you want enlarged and
press Enter.
e) Move the cursor below and to the right of the location you want enlarged and
press Enter.
f) The box is then enlarged to fill the screen.

10.  Finding the intersection point of two graphs.
a) Enter two functions on separate "Y=" lines and press GRAPH.
b) Press 2nd,  CALC.
c) Press 5 to select intersect.
d) Move the cursor near the point of intersection.
e) Press ENTER two more times.
f) The point of intersection will appear at the bottom of the screen.

11.  Solving an equation in one variable. (Also known as finding the roots or x-axis intercepts.)
a) Enter the function and graph.
b) Press 2nd, CALC.
c) Press 2 to select zero.
d) Move the cursor to the left of the intercept and press ENTER.
e) Move the cursor to the right of the intercept and press ENTER.
f) Press ENTER again.
g) The root wilI appear at the bottom of the screen.

12.  Finding coordinates to graph a parabola by hand.
a)  Enter the graph in your calculator as described above.
b)  Next locate the vertex by pressing [2nd],[CALC], and pressing either 3 or 4, depending on
whether the vertex is a minimum or maximum for the parabola.
c)  Move the cursor slightly to the left of the vertex and press [ENTER].
d)  Move the cursor slightly to the right of the vertex and press [ENTER].
e)  Finally, move the cursor approximately to the vertex and press [ENTER].  The x- and y-values
for the vertex will appear at the bottom of the screen.
f)  Press [2nd],[TABLE].   (Be sure that your independent variable is set for Ask.  If not press
[2nd], [TBLSET] and highlight "Ask" (opposite Indpnt.)
g)  Enter two more values for "x" in the table and the corresponding values for "y" will appear.
h)  Use these coordinates and the symmetry property of a parabola to graph the parabola on a
sheet of paper. (NOTE:  If the vertex is at an integer value, you can find the vertex from the
table.)

13. Graphing Inequalities.
a)  Write each equation in the y =mx + b format and enter them into  the "Y=" positions.
(Remember  that you may need to change the direction of the inequality sign if you have to
multiply by -1 during the rearranging of the equation.)
b)  Shading of the graph is determined by the symbol to the left of the "Y=" entry.  Using the left
arrow, move the cursor all the way to the left of the Y= symbol.
c)  Pressing ENTER in that position will display different symbols.  For < or <, press ENTER
until the upright triangle is displayed.  For > or >, press ENTER until the upside down
triangle is displayed.
d)  After you have the correct symbol displayed, press ENTER to graph the inequality.

14.  Marking points on a graph.
A few students who capture screens like to have marks on graphs.  Although some would
consider this more trouble than it's worth, I'll include it for those brave souls who must have
them. Although marks can be put directly on the graphing screen, that method uses the dot as
a mark and it cannot be seen when imposed on the line of a graph.  So, I will describe the
method of entering marks from the home screen where you can select a + or a box..
a)  First, if you are a little picky about having the marks line up exactly on the graph, you
should press ZOOM, 4 to select ZDECIMAL.  Then graph your function and see if it the x-
and y-values that you are interested in appear on the screen.  If not, press ZOOM, cursor
over to MEMORY and press 4.  Then make the X- and Y-Fact integers larger than 1.  Then
press ZOOM, 3 to change the x- and y-scales.
b)  Go to the home screen to start the procedure.  The syntax is Pt-On(x,y,mark.  So, press
2nd,  DRAW and cursor over to POINTS.
c)  Press ENTER and Pt-On( will appear on the home screen.
d)  Enter the x-coordinate, y-coordinate, and the mark number. For the mark, 1=a dot, 2 = a
box and 3 = a cross.  I will use 3.  Let's say we graph X2 and we want to mark coordinates
(2,4).  Then your entry will be Pt-On(2,4,3.  (The mark will be a +.)
e)  To mark additional points, press 2nd, ENTRY and change the x-, y-coordinates to those for
the next point.  Continue this for additional points.
f)  To erase all points, press 2nd, DRAW, ENTER.

V. SPECIAL FUNCTIONS
1.  Changing from radian measure to the degree mode.
a) Press the MODE key.
b) Move the cursor to either radian or degree to match the units of your angle.
c) Press Enter.
d) Press CLEAR or 2nd, QUIT to return to the calculator screen.

2. Graphing piecewise functions or  functions on an interval.
a) To graph a function on the interval x < a, enter the function followed by
(x<a).
b) To graph a function on the interval x > a, enter the function followed by (x>a).
c) To graph a function of the interval a<x<b, enter the function followed by
(x>a)(x<b).

VI.  CALCULUS
1.   Finding the numerical derivative of a function:
a) Press the Math key.
b) Press 8 to select nDeriv(.
c)  Press 2nd, Y-VARS; select the variable you want and press ENTER.
d)  Enter the name of the independent variable, probably X.
e)  Enter the value where you want to find the derivative and press enter.

2.  Determining the value of the derivative from points on a graph.
a) Enter the function and graph.
b) Press 2nd, CALC.
c) Press 6 to choose dy/dx.
d) Move the cursor to the desired point and press ENTER. The value of the
numerical derivative will appear at the bottom of the screen.

3.  Drawing a tangent line at a point.
a) Enter the function and graph.
b) Press 2nd, DRAW.
c)  Press 5 to select Tangent(.
d)  Move the cursor to the point of tangency desired and press ENTER.
e)    To clear the tangent line, press 2nd, DRAW and then  ENTER.

4.  Calculating the value of a definite integral:
a) Press the MATH key.
b) Press 9 to select fnInt(.
c) You will now enter an expression in the form Y,X,a,b inside the parentheses.
In that expression, Y is the expression you’re integrating; for example Y1, X is the
variable of integration, usually X; a is lower limit and b is the upper limit.
d) For the expression to be integrated, you can either choose a variable entered
into the Y= screen, or you can enter the expression itself.  As an example,
you might have  fnInt(Y1,X,1,2 with your expression entered into Y1, or you
might have fnInt( x2,x,1,2 where you have entered the expression x2 yourself.
Notice that you must enter Y1 from the Y-VARS menu if you use that
method.
e) Press the ENTER key to see the value of the definite integral.

5.  Alternate procedure for finding the value of a definite integral.
a) Press the ZOOM key.
b) Press 4 to select ZDecimal.  (You don’t have to do this step, but it will be
easier to set your limits if you do.)
c) Press the Y= key.
d) Enter the function you are integrating.
e) Press the GRAPH key.
f) Press 2nd, CALC.
g) Press 7 to select the integral.
h) Move the cursor to the lower limit of integration and press the ENTER key.

i) Move the cursor to the upper limit of integration and press the ENTER key.

j) The integrated region will be shaded, and the value of the definite integral will
appear at the bottom of the screen.   (NOTE:  Be careful about curves that go below the x-axis.)

VII.  MATRICES:
1)  Entering a matrix:
a)  Press 2nd, MATRIX, move the cursor to EDIT.
b)  Move the cursor to the matrix number you want to edit or enter numbers in,
and press ENTER.
c)  Enter the number of rows and press ENTER; then enter the number of
columns and press ENTER.
d)  Enter each value of the matrix and press ENTER after each value.
e)  Press 2nd, QUIT to go to the home screen.

2)  Multiplying two matrices [A] * [B]:
a)  Enter the data into matrices [A] and [B] and press 2nd, QUIT to go to the
home screen.
b)  Press 2nd, MATRIX, select the matrix you want as the first in the product, [A],
and press ENTER.
c)  Press the multiply symbol.
d)  Press 2nd, MATRIX, select the matrix you want as the second in the product,
[B], and press ENTER.
e)  Press ENTER to perform the multiplication step.
f)  Remember that the numbers of columns in [A] must equal the number of
rows in [B] or you will get a dimension error.
3)  Doing other matrix math:
a)  Press 2nd, MATRIX and cursor over to MATH.  There you will see a list of
operations that you can do.  To do find the determinant, use Det.  To find
the transpose, use T.
b)  After you select the operation you want, press ENTER.
c)  Press 2nd, MATRIX, select the matrix you want to operate on, and press
ENTER.

NOTE:  You can do any of the elementary row operations.  They are very useful for doing the arithmetic for Gauss or Gauss-Jordan elimination, but a little time is required to get the hang of doing row operations. So, since most students don’t take the time to use those functions, I’m not going to include them.  Instead, I’ll give you my Website as a reference for doing those operations if you want to do them.  First go to my Website:  http://www.anglefire.com/pro/fkizer
Go to the listing “TI FAQs” in the navigation bar on the left.  Click on the link “More Detailed Page 1”. That will take you to a long page of 40 FAQs.  Cursor down to the answers and then down to answer (21). That will give you the procedure for doing the row operations.  Alternately, to find item 21,  you can use Find under the Edit menu and enter (21) in the dialog box.  Then click Next to find the answer.

5)  Doing rref and ref:
a)  First enter your matrix as in item 1 of this section and press 2nd, QUIT to go to the home
screen.
b)  Press 2nd, MATRIX, and move the cursor to MATH.
c)  Select item A for ref or B for rref as you choose and press ENTER.  Note that if you know you
want to use item (for rref or ref) just press ALPHA; then the appropriate letter.
d)  Press 2nd, MATRIX and press the number for the matrix you want to operate on.
e)  Press ENTER and the answer will appear.
f)  If you want the answer in fractions, skip step e) and press MATH, ENTER, ENTER.

6)  Solving a system of linear equations:
Let's take the following set of simple equations:
3x -3y = -2
2x +y = 1

Entering the matrix:
a)  Press 2nd, MATRIX, move the cursor to EDIT.
b)  Move the cursor to the matrix (A, B, etc)  you want to edit or enter numbers in,
and press ENTER.  (Alternatively, you can press the number opposite the matrix you choose.)
c)  Enter 2 for the number of rows and press ENTER; then enter 3 for the number of
columns and press ENTER again.
d)  Enter each value of the matrix and press ENTER after each value.  Enter only the coefficients of the
variables and the constants.  Do NOT enter variables, or plus signs, but do enter negative signs.
Enter the numbers 3, -3, -2, 2, 1, 1 and press ENTER after each number.
e)  When your finished, press 2nd, QUIT to go to the home screen.
Solving the system of equations using the rref operation:
f)   From the home screen, press 2nd, MATRIX, and move the cursor to MATH.
g)  Select item B for rref and press ENTER.  Alternatively,  you can press ALPHA; then B to paste rref(
to the home screen.
h)  Press 2nd, MATRIX and press the number for the matrix you want to solve, for example [A].
i)  If you want the answer in fractions, press MATH, ENTER, ENTER, otherwise, just press ENTER and

7)  Solving linear programming problems using the simplex method.
You will need a program for this.  You can either copy one of my simplex programs from this
website and enter it by hand or copy someone else's program.  STCC students may call me at
333-5989 to arrange to have this program transferred electronically to their calculator.

VIII.  SEQUENCES:

1)  Find the first four terms of the sequence an =3n-2.
a)  Press 2nd, LIST, cursor over to OPS and press 5.  seq( will be pasted to the home screen.
b)  Enter 3; ALPHA; N; -;ALPHA; N;, ; 1;, ;4  You now should have seq(3N-2, N, 1,4 on the
home screen.  (It is not necessary to close the parentheses in this situation.)  (Note that
the second "N" is just defining the variable that you want to use.)
c)  Press ENTER and {1,4,7,10} will be displayed.

2)  Find the sum of the sequence above.  This type problem will usually be written using the
summation symbol, Σ.
a)  Press 2nd, LIST; cursor over to MATH and press 5.
b)  Press 2nd, LIST, cursor over to OPS and press 5.  sum(seq(  will now appear on the
home screen.
c)  Enter 3; ALPHA; N; -;ALPHA; N;, ; 1;, ;4  You now should have sum(seq(3N-2, N, 1,4
displayed on the home screen.
d)  Press ENTER and 22 will be displayed.

3)  Find the cumulative sum of the above sequence.
a)  Press 2nd, LIST; cursor over to OPS and press 6.
b)  Press 2nd, LIST, cursor over to OPS and press 5. cumSum(seq(  will now appear on the
home screen.
c)  Enter 3; ALPHA; N; -;ALPHA; N;, ; 1;, ;4  You now should have cumSum(seq(3N-2, N, 1,4.
d)  Press ENTER and 22 will be displayed. Note that this method gives the sum after each
increment of the variable N.
4)  Find the 5th term of the above sequence.  Although this is easily done by hand, some
students like to check their results. So here's how to do it with your calculator.
a)  Press 2nd, LIST, cursor over to OPS and press 5.  seq( will be pasted to the home screen.
b)  Enter 3; ALPHA; N; -;ALPHA; N;, ; 5;, ;5  You now should have seq(3N-2, N, 5,5 on the
home screen.   (Note that the same number is entered for the beginning and end.)
c)  Press ENTER and {13} will be displayed.

IX.  Complex Numbers:

1.  Finding Solutions of a Polynomial with Complex Coefficients:

Since the solver will not handle complex numbers, we must resort to other methods. Let's consider the equation
(2-3i)x² +(4+i)x +(1-3i) = 0.
a)  Press MODE, cursor to FLOAT, move over to highlight 5, and press ENTER; then move down to the 7th line and highlight
a+bi and press ENTER.  Press 2ND, QUIT to go back to the home screen.
b)  Press 2, -, 3, 2ND, i (the second function of the decimal point), STO, ALPHA, A, ENTER.  This stores the
coefficient of x² in variable "a."
c)  Perform the same operation for the b, and c, the coefficient of x and the constant.
d)  Now, press 2ND,
√, ALPHA, B, x2 , -, 4, ALPHA, A, ALPHA, C, ), STO, ALPHA, D.  This stores the discriminant
in variable d.  You can write this result down if you want it.
e)   Press (, - (negative sign) , ALPHA,  B, +, ALPHA, D, ), ÷, (, 2, ALPHA, A, ), ENTER.  The first value for "x" will
be displayed.
f)  Press 2ND, ENTRY (the ENTER key), and change the "+" sign between B and D to -.
g)  Press ENTER and the second value for "x" will be displayed.
NOTE:  You may want to change your number format back to Float.
Here's a simple program that you can enter to do this:

PROGRAM: CMPXPOLY

"FKIZER 091207"
:a + bi

:Fix 5
: Prompt A, B, C
:
√(B² -4AC)→D
: ClrHome
:Disp "X1=", (-B+4AC)/(2A)
:Disp "X2=", (-B-4AC)/2A
:  Float   (This last step sets the calculator number format to Float.  If you don't want that, leave it out.)

X. Combining and Connecting Operations:

1) Doing expressions with several terms:

One of the powerful tools for use with a calculator is combining terms and connecting terms to perform
several operations sequentially.  Let's take for example the index of Shannon which is used in ecological
assessments.  This is the expression:
H' = -
Σ(pi *ln (pi)   (where pi is each Ni/sum (Ni) in the table below.
This table represents the equation as applied to four different types, i, of trees found in 100 m² of forest.

 i Ni pi ln (pi) pi*ln(pi) 1 6 .3 -1.2034 -.3612 2 4 .2 -1.6094 -.3219 3 2 .1 -2.3026 -.2303 4 8 .4 -0.9163 -3.665 SUM 20 -1.27985

H' = 1.27985 the negative of SUM in the table above.
Doing it all in one step:
The values for Ni, pi, ln (pi), and pi*ln (pi) can be entered in lists L1, L2, L3, and L4 with one series of expressions
as follows:
a)  First clear the four lists by pressing STAT, 4 to paste ClrList to the home screen.
b)  Then enter the four lists by pressing 2ND; then the key for the list number for each list to be cleared.
c)  Enter the values for Ni in L1 by pressing STAT, ENTER and entering the numbers.
d)  Now press 2ND, QUIT to go to the home screen.
e)  Enter the following on the home screen: L1/sum (L1)-->L2:ln (L2)-->L3:L2*L3-->L4: -sum(L4).  Note that sum(
is entered by pressing 2ND, LIST, MATH, 5 and the colons are entered by pressing ALPHA, and the decimal
point button.
f)  Press ENTER and all of the data in the table above will be entered in the lists except the sum and that will be
displayed on the home screen.
Suppose you only want the answer without the data for various steps.  Do this:
a) After clearing the lists and entering the data as in steps a through d above, enter this formula:

-sum((L1/sum (L1))(ln((L1/sum (L1))).  The only entry that might not be obvious is sum(, which can be
obtained by pressing
2ND, LIST, MATH, 5

XI.  TRANSFERRING PROGRAMS AND DATA:

1)  I will assume that both calculators are TI-83 Plus:
a) Turn both calculators off and plug in the unit-to-unit cable for both calculators.
b) Turn on both calculators and press 2nd, LINK on both. Cursor over to
program to.
c) Press ENTER on the receive calculator. The word "Waiting"  should appear.
d) On the sending calculator, cursor down to Prgm and press ENTER.
e) Cursor down to the program you want to transfer and press ENTER. The
program that you selected will be marked with a square "dot."
f) Cursor over to TRANSMIT press ENTER.
g)  If everything is connected satisfactorily, transmission of the program should
start. Otherwise,  you'll get a transmit error after a few seconds.

XII.  PROBLEMS:

1)  Problems with trigonometric functions:  The most common problem with trig functions is not having the MODE set to the dimension of the number entered.  For example, students may have entered degrees, but have their calculator MODE set to radians.  To correct that, see “Changing the MODE in section I.

2)  If your calculator hangs up and you are unable to correct the problem, first try online or other places that provide help.  If you are unable to get help, you can reset the calculator.  Do that as follows:
a)  Press 2nd, MEM, press 3.
b)  Press 7 to select RESET.
c)  Press 2 to select Defaults.  Your calculator should now be reset.

Page Activated: 8/6/06
Revised: 12/6/06