Graphing a Function on TI-84 Plus CE

 First, to type in a function, press the “y=” button.

• Type in the given function as is. If the function is a rational function, please don’t forget to put parentheses around its numerator and denominator or use the fraction form.
•  To type [latex]x[/latex], use “X, T, [latex]\theta[/latex], n” button.

 Second, to change the view of the function, press the “Window” button.

• If the window is given, please change the window: [Xmin, Xmax, Xscl] X [Ymin, Ymax, Yscl] 
• Default window is [-10, 10, 1] X [-10, 10, 1]

 Third, to see the graph of the function, press the “Graph” button.

 Lastly, if you want to go back to the default window setting, press the “Zoom” button. Then choose “#6: ZStandard”

Finding a Minimum/Maximum Value on TI-84 Plus CE

 First, graph the function on TI=-84 using the “y=” button and the “graph” button.

 Second, to find the minimum or maximum (or vertex or turning point) of the function, press the “2nd” button and the “trace” button in order, which is the “calc” button. Then choose “#3: minimum or #4: maximum.”

• Left Bound [latex]\rightarrow[/latex] click on the left side of the minimum/maximum point
• Right Bound [latex]\rightarrow[/latex] click on the right side of the minimum/maximum point
• Guess [latex]\rightarrow[/latex] optional; don’t need to guess ^^

Finding Zeros on TI-84 Plus CE

 First, graph the function on TI=-84 using the “y=” button and the “graph” button.

 Second, to find the real zero (or [latex]x[/latex]-intercept) of the function, press the “2nd” button and the “trace” button in order, which is the “calc” button. Then choose “#2: zero.”

• Left Bound [latex]\rightarrow[/latex] click on the left side of the minimum/maximum point
• Right Bound [latex]\rightarrow[/latex] click on the right side of the minimum/maximum point
• Guess [latex]\rightarrow[/latex] optional; don’t need to guess ^^

If there are more than one zero, repeat the second step.

Solving Polynomial Equations and Inequalities on TI-84 Plus CE

First, move all terms to the lefthand side of equal sign or inequality symbol. Then express the given equation or inequality as [latex]y = 0, y \geq 0, y > 0, y \leq 0, or y < 0[/latex].

Second, set “[latex]y[/latex] = (lefthand side of the equation or inequality)”

 Third, graph the function on TI=-84 using the “y=” button and the “graph” button.

Fourth, find the distinct parts of the graph:

• If [latex]y>0[/latex], above the [latex]x[/latex]-axis.
• If [latex]y=0[/latex], on the [latex]x[/latex]-axis.
• If [latex]y<0[/latex], below the [latex]x[/latex]-axis.

Lastly, find the interval(s) of [latex]x[/latex] values where the part you found in the previous step. It is the solution of the equation or inequality.

Using Matrices to Solve Linear System on TI-84 Plus CE

First, find the augmented matrix of the linear system.

 Second, to type in the augmented matrix into TI-84 Plus CE, press the “2nd” button and the “[latex]x^(-1)[/latex] button, which is “matrix.” Then go to Matrix> EDIT> 1: [A].

• Type in the dimension of the matrix (# of rows X # of columns).
• Type in the entries.
•  When you are done with typing in entries, don’t forget to “quit” using the “2nd” button and the “mode” button.

 Third, to see the matrix you typed in, go to “matrix” using the “2nd” button and the “[latex]x^(-1)[/latex]” button. Then go to Matrix > NAMES > 1: [A].

 Fourth, to find “rref” (reduced row echelon form), go to “matrix” using the “2nd” button and the “[latex]x^(-1)[/latex]” button. Then go to Matrix > MATH> B: rref. Now go back to “matrix.” This time go to Matrix> NAMES> 1:[A] and then close the parenthesis “).”

 Lastly, to clear matrices in TI-84 Plus CE, go to “memory” using the “2nd” button and the “+” button. Then go to Memory> 2: Mem MAnagement/Delete> 5: Matrix. Click “del” to clear any matrix.