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 ) go to “WINDOW” go to F1-Tools Select #9: Format 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)

F3 Calc. Functions Differentiate: Format is d (f(x) ,x) i.e. d (x2+2,x) Example: On calc.: Answer:

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

(F3) Integrate: Indefinite Integral:  Format on calc. is: 

Integration Examples Example: On calculator: Answer:

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” 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, zeros, and intersection points 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., Min., and Intersection 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. 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). Solution: (-1.646, -1.646), (3.646, 3.646)

Generating a Table for Polar Equations MODE: Change Graph Mode to Polar Press and F1 (Y=) Enter equation under r1 Press and F4 (TblSet) and input your initial under tblStart and the under and F5 to view the table

Polar Equation Example Solution: Press F1 On the Y= Menu, Press F4, F5 to view the table On TblSet: tblStart = 0,  r .7854 1.414 1.571 2 2.356 When  =2.356, r=1.414

Euler’s MODE: Change Graph Mode to Diff. Equations Press and F1 (Y=) Enter initial x condition under t0= and initial y under yi1= Use t for x and y1 for y when inputting the differential equation While still on the Y= page, press F1 and scroll down to 9: Format, press enter Scroll down to Solution Method and choose Euler Press F2 to go to the Window Page. Change the tstep to your Press and F4 (TblSet) and input your initial x under tblStart and the under and F5 to view the table

Euler’s Example Example: Solution: On the Y= Menu, When x=2.5, y=-5 t 1 4 1.5 -2 2 2.5 -5 When x=2.5, y=-5

Special Functions Graphing Parametric: Graphing Polar: 1) Mode Graph Parametric Remember: The functions are x(t) and y(t) not y(x) Graphing Polar: 1) Mode Graph Polar 2) Mode Complex Format Polar Remember: Press [Enter] to save Remember: Use Theta , not x

THE END! Happy Calculating!