Calculator Information
For all prep math classes, Pre-Algebra (MAT0012) or Beginning Algebra (MAT0024), students can use any scientific calculator. For college level math classes, Intermediate Algebra (MAT1033) and beyond, students will need a graphing calculator, such as a Texas Instruments TI-83 or TI-83 Plus. Other calculators can be used, but instructors discuss and instruct using the TI-83 or TI-83 Plus.
User Guides
TI-83 Plus or TI-84 Graphing Calculator Hints
NOTE: All highlighted text represents a calculator key!
General information:
| Zoom | 6: ZStandard | Two steps to make a graph go 10 units in every direction. | |
| Left arrow | Right arrow | Used to move your cursor on the graphing screen. | |
| Up arrow | Down arrow | Changes the equation that calculator is referring to. | |
| y = | Allows you to put in an equation that is solved for 'y'. | ||
| x,T,Ø,n | Allows you to put the variable 'x' into an equation. | ||
| Trace | Left or Right arrow changes info | Finds mostly approximate decimal values for 'x' and 'y'. | |
| Trace | Pick 'x' value | Gives matching 'y'. The 'x' value must be on graphing screen. | |
| Trace | 0 (zero) | Gives you the y - intercept. | |
| Window | xmin & xmax | Sets lowest (left) and highest (right) value of the x-axis. | |
| Window | ymin & ymax | Sets lowest (bottom) and highest (top) value of the y-axis. | |
| Graph | Zoom | 0:Zoomfit | Helps to find a graph that does not show on your screen. |
Parentheses: Put on all numerators and denominators that have 2 or more terms.
Example: 
Put in calculator for graphing as: (5x + 7) / (2x – 3)
How to find an exact ‘x’ value on a graph:
You are given a ‘y’ value from your graph and asked to find the matching 'x' value.
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y = |
y2 = |
Enter given 'y' value into the equation. | |
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2nd |
Trace |
5: intersect |
First curve? Enter Second curve? Enter Guess? Enter If there are 2 or more intersections, just before you guess use your left or right arrow to put cursor on the intersection that you want information on. |
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Calculate |
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Calculations: 2nd Trace
| 2: zero | Finds the 'x' intercept. | Left Bound? Place cursor to the left of point you are looking for on the graph. Enter Right Bound? Place cursor to the right of point you are looking for on the graph. Enter Guess? Enter |
| 3: minimum | Finds vertex of parabola facing up. | |
| 4: maximum | Finds vertex of parabola facing down. | |
| 5: intersection | Finds intersection of 2 graphs. | First curve? Enter Second curve? Enter Guess? Enter If there are 2 or more intersections, just before you guess use your left or right arrow to put cursor on the intersection that you want information on. |
How to find a line of Linear Regression:
What you are finding is a line that best fits (goes as close as possible) to all of
the points that you scattered about your graph (scatterplot).
Entering Data:
|
Stat |
Section that will allow you to enter your scatter plot points. | ||
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1: Edit |
Enter |
Allows you to erase, change, or add point information. | |
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L1 |
Clear |
Enter |
Clears all L1 entries (Use arrows keys to put marker on L1). |
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L2 |
Clear |
Enter |
Clears all L2 entries (Use arrows keys to put marker on L2). |
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L1 |
x-value |
Enter |
Put marker on dotted line and enter all your x-values. |
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L2 |
y-value |
Enter |
Put marker on dotted line and enter all your y-values. |
| Note: You can change any value by highlighting the incorrect value and typing in new value. Enter | |||
Calculating equation:
| Stat | Section that will allow you to calculate your equation. | |
| CALC |
Right arrow |
Highlights the CALCulation section. |
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4 |
4: LinReg(ax+b) | Calculates the slope (a) and the y-intercept (b) of your linear equation. |
| Note: The calculator may also display values of r2 and r which is used by some instructors. | ||
Graphing equation:
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y = |
y1 = |
Will put your equation into any 'y' that you put your cursor on. | |
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VARS |
5 |
5: Statistics |
Will move you to next screen for finding your equation. |
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EQ |
Right Arrow twice
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This will show a screen with a list that includes 1: RegEQ | |
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1: RegEQ |
Enter |
Returns you to the y= screen showing your equation. | |
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GRAPH |
Adjust window |
Your now have your equation on the screen. | |
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Note: The following steps will include all your scatterplot points on with your graph. |
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y = |
Up arrow |
Plot1 should now be highlighted and flashing. | |
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Enter |
The Plot1 colors should reverse themselves which turns on the Plot1. | ||
| GRAPH | Your graph should now include boxes that represent your points. | ||
| Note: Leaving the Plot1 when doing other work will often give you an error message. | |||