So you don’t know how to use a TI-89…

Rita Korsunsky

Helpful Facts MODE

To change the graph format, go to “Graph…”- You can change the format to Function, Parametric, Polar, or Diff Equations.

Make sure to have your “Angle…” set to Radians in order to graph trig. functions

Exact/Approx: Approximate will give you decimal approximations while exact produces answers as fractions or in terms of other expressions

To make the window squared, go to F2 , Zoom Squared.

To change the graph order

(to get to simultaneous mode )

1. go to “WINDOW”

2. go to F1-Tools

3. Select #9: Format

4. Graph order (SEQ => SIMUL)

Helpful Facts Absolute Value: Press 2nd and 5 [Math],Number, abs

Factorial (!): Press and Logarithmic:

1. Press CATALOG key. 2. Press the 2nd and alpha keys 3. Press 4 to get to the L options 4. Scroll down to “log(” and press enter to insert it.

Don’t forget to close all parenthesis!

Using the F2 Function

Press “F2” for the algebra menu. The “solve(” function would automatically be highlighted. Press “Enter” (or the “1”) button to insert the function.

F2 Solve

• Solve : Format is Solve(equation=#, x)

Example: Solve (x2+2x-3=8,x)

• Zeros: This will give you the same results as solve, the difference is that with the zero function, you must have your equation=0

Answer: x= 2.461 or x= -4.461

Solve Continued

•By setting the equation to 0, roots will be displayed if they exist. Make sure to scroll through ALL roots. If no solutions, “false” will be displayed.

Example: x3+ 3x2-5x-8=0

Roots: x = 1.88897 or x = -1.1252 or x = -3.7637

F2 continued

• Factor/Expand :

Format is Factor(equation=0)Expand((x-3)(x+5))

Example: factor (y2 -4=0)Answer: (y+2)(y-2)

The Graph To add a graph, go to ‘Y=‘ (Diamond + F1)

Be sure to press enter after inputting the equation!

You can add multiple graphs (y1, y2, etc.)

The Graph (contd.)

To set the bounds of the graph, go to ‘Window’ (Diamond + F2) xmin, xmax, ymin, ymax =

bounds of the graph xscl, yscl = interval of

tick marks on the axes

Go to ‘Graph’ (Diamond + F3) to view graph

Zooming Press “” and F3 to view the graph Press F2 “Zoom”

2. ZoomIn 3. ZoomOut

Move the cursor to where you want to zoom in/out

Press enter

Tracing a Graph Press Diamond + F3 to view your graph

Press F3 ‘Trace’ Press Left and Right to move along

graph Press Up and Down to switch graphs Use 2nd + Left/Right to move faster

The Graph (contd.)

This method can be used to find maximums, minimums, and zeros.

Example: Finding Zeroes

•Zero: From the Y= menu ( F1),, press “” and “F3” to graph.

•When the graph is finished graphing, press “F5,” then scroll down to “2: Zero” and press “enter. ” (Max. and Min., are also options)

The Graph (contd.)

• Select a lower boundary (any point left of the zero) by using your left and right arrows to move along the graph and press “enter.” Then select an upper boundary (any point right of the zero) and press “enter”. The zero is then displayed.

Example: , Find Minimum.xxy 22 Solution: Minimum at (1,-1)

Intersection Points Press “” and F3 to view graph F5 ‘Math’ -> 5. Intersection Select the two graphs that intersect Select the lower/upper boundary

like before

Example: ,

Find intersection points (2).

2 6,y x x y x

Solution: (-1.646, -1.646), (3.646, 3.646)

MODE: Change Graph Mode to Polar

Generating a Table for Polar Equations

and F5 to view the table

Press and F1 (Y=) Enter equation under r1 Press and F4 (TblSet) and input your initial under tblStart and the under tbl

Polar Equation Example

Example: 536.2

4

3 when eapproximat Find

sin2

r

r

r

0 0

.7854 1.414

1.571 2

2.356 1.414

When =2.356, r=1.414

Solution: Press F1

On the Y= Menu, Press F4, F5

to view the table

On TblSet: tblStart = 0,

sin2r

4

tbl

Special Functions

Graphing Parametric:1) Mode Graph Parametric• Remember: The functions are

x(t) and y(t) not y(x)

Graphing Polar:1) Mode Graph Polar2) Mode Complex Format Polar• Remember: Press [Enter] to save• Remember: Use Theta , not x

F3 Calc. Functions

Differentiate:Format is d (f(x) ,x)

i.e. d (x2+2,x)

Example: On calc.:)58( 3 xx ),58( 3 xxxd

524 2 xAnswer:

Differentiation at the Point

To Differentiate y=f(x) at x=2

Graph y=f(x)

View graph

Press F5

6 for derivative

dy/dx

Enter

Plug in 2 for x

Enter

THE END! Happy Calculating!