## 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.

### 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.

 y = y2 = Enter given 'y' value into the equation. 2nd Trace 5: intersect First curve?  Enter   Second curve?  Enter   Guess?  EnterIf 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. Calculate

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. EnterRight Bound?   Place cursor to the right of point you are looking for on the graph. EnterGuess?  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?              EnterIf 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. 1: Edit Enter Allows you to erase, change, or add point information. L1 Clear Enter Clears all L1 entries (Use arrows keys to put marker on L1). L2 Clear Enter Clears all L2 entries (Use arrows keys to put marker on L2). L1 x-value Enter Put marker on dotted line and enter all your x-values. 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. 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.