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TI-89 Calculator Steps:

Graphing an Equation (Use ( to access Y=, WINDOW, GRAPH, TblSet, and TABLE)

• Y=[pic] enter the equation(s)

• Adjust window

▪ WINDOW [pic] Enter xMin, xMax, and xScl

(use given x-intervals or make a logical guess from the problem statement to get xMin and xMax values, for xScl enter the desired spacing on the x-axis)

▪ Either manually set yMin, yMax or F2 (ZOOM) [pic] ZOOMFIT

Using the Table to see x and y values (this may be useful in setting the window)

• Y = [pic] enter the equation

• TBLST [pic] at TblStart enter a starting value for the table

at [pic]Tbl enter the desired spacing

at Indpnt select Auto

• TABLE [pic] Scroll through the table to see x and corresponding y values.

Evaluate the equation for a given x-value (2 different methods)

• Graph the equation (make sure the given x-value is between xMin & xMax)

▪ F5 (MATH) [pic] VALUE [pic] enter x-value [pic] ENTER

or

▪ F3 (TRACE) [pic] enter x-value [pic] ENTER

Given a y-value, solve for x (used in solving equations)

Crossing Graphs Method

• Graph both the left-hand and right-hand side of the equations

• Find the intersection

▪ F5 (MATH) [pic] INTERSECTION

▪ First curve? Make sure the cursor is on the first curve and hit ENTER

▪ Second Curve? Make sure the cursor is on the second curve and hit ENTER

(If only 2 functions are entered in Y=, the calculator will automatically move to the desired curves, so after choosing INTERSECTION, you need only hit ENTER 2 times)

▪ Lower Bound? Move the cursor to the left of the intersection and hit ENTER

▪ Upper Bound? Move the cursor to the right of the intersection and hit ENTER

Single Graph Method

• After setting the equation = 0, graph the non-zero side

• Find the x-intercept

▪ F5 (MATH) [pic] ZERO

▪ Lower Bound? Move the cursor to the left of the x-intercept and hit ENTER

▪ Upper Bound? Move the cursor to the right of the x-intercept and hit ENTER

Find the maximum and minimum

• Graph the equation

• F5 (MATH) [pic] MINIMUM or MAXIMUM

• Lower Bound? Move the cursor to the left of the max/min and hit ENTER

• Upper Bound? Move the cursor to the right of the max/min and hit ENTER

Do not use TRACE or the TABLE, they will only give you an approximation!!

How do you do indirect proof in logic? SYMBOLIC LOGIC INTRODUCTION TO INDIRECT PROOF Indirect proof is based on the classical notion that any given sentence, such as the conclusion, must be either true or false. We do indirect proof by assuming the premises to be true and the conclusion to be false and deriving a contradiction.