From your home screen, if you have calculated a value which is not an integer value, you can determine whether or not it is a rational number and can be written as an exact fraction by hitting

- Graph the two functions by entering the slope-intercept form of the
lines into
*Y1*and*Y2*. These are located under the*Y=*button. - Go to
*CALC*which is found by pressing*2nd TRACE*. - Select option
*5:intersect*. - The calculator will prompt you for the first and second curves you want to
intersect. The cursor will blink on a function and show the function name in the
upper left corner of the screen. When it blinks on
*Y1*, press*ENTER*& when it blinks on*Y2*, press*ENTER*. - The calculator will then ask you to guess where the intersection point is
located. Use your
*right*and*left*arrow keys to move to the intersection point and press*ENTER*. - The intersection point will appear at the bottom of the screen.

- Enter your x and y values into lists. To do this, hit
*STAT*and select*1:Edit...*. If you have anything in*L1*or*L2*, cursor up to the name of the list, hit*CLEAR*and*ENTER*. Now just enter in your values one at a time by pressing*ENTER*after each number. - To find the regression equation, first hit
*STAT*, cursor right to*CALC*and select option*4:LinReg(ax+b)*. Now press*2nd 1 , 2nd 2 ,*to specify the x list and y list.**(REMEMBER THE COMMAS! You do not have to specify the lists if you are using L1 and L2 for your x and y-values, respectively.)**Hit*VARS*, cursor right to*Y-VARS*, select*1:Function...*and*Y1*(or whichever function you would like) to specify where the regession equation will be saved. You should now see the following on your home screen:*LinReg(ax+b) L1, L2, Y1*or*LinReg(ax+b) Y1*(if you are using L1 and L2 for your lists) - Now, press
*ENTER*. The following should appear on your screen:*LinReg(ax+b)*

y=ax+b

a=....

b=....

r^2=....

r=....*Y1*. If you don't have the*r*stuff, then you need to turn your diagnostics on. To do this, hit*2nd 0*, and cursor down to select*DiagnosticOn*. When this comes up on your home screen, press*ENTER*and it should say*Done*. - To graph the regression line with the data points, first make sure your stat plot
is turned on. To do this, hit
*2nd Y=*and select*1....*by pressing*ENTER*. You can then highlight any of the options you would like. Now just hit*GRAPH*. If you don't see anything, adjust your window size under*WINDOW*and*ZOOM*. - To find a y value from your regression line when given an x value, go to
the main calculator screen and call up your function name (
*VARS*, cursor right to*Y-VARS*, select*1:Function...*and*Y1*(or whichever function your line is in)) and then open the left parenthesis, type the x value and close your parenthesis. OR... hit*CALC (2nd TRACE)*and select option*1:value*. Then just enter the value for x. - To find an x value from your regression line when given a y value, enter the
y value under
*Y2*and then find the intersection point between*Y1*(your regression line) and*Y2*.

If you have a TI-83 Plus or any version of the TI-84, when you see directions to hit the

**Entering a Matrix**- Hit
*MATRX*. - Cursor right two places to
*EDIT*and hit*ENTER*. - Enter the size of the matrix.
**(ROW NUMBER FIRST, COLUMN NUMBER SECOND!!!)** - Enter the matrix elements. If you enter the elements and press
*ENTER*after each element, the cursor will move left to right across the rows and then down to the next row and continue in the same fashion until you reach the last element of the matrix. You can always move around to different elements with your cursor keys, too.

- Hit
**Calling a Matrix for Computation**- Make sure you are on the home screen before you begin. To do this, hit
*2nd MODE*to quit. - Press
*MATRX*and cursor down under the*NAMES*list until you get to the matrix you want and hit*ENTER*. The name of the matrix you need to do computations with will now be on your homescreen.

- Make sure you are on the home screen before you begin. To do this, hit
**Matrix Transpose**- Call the matrix you would like to transpose from the home screen.
- Hit
*MATRX*, cursor right to*MATH*and select option*2:T*. - You should now see the symbolic representation of transposing your matrix.
To actually see the transpose, hit
*ENTER*.

**Square Matrix Inverses**- Enter the matrix for which you would like to find the inverse.
- Call that matrix from your home screen.
- Hit the x inverse button (
*x^-1*) which is directly below the*MATH*key and press*ENTER*.

**Fast RREF (This only works when the #rows is less than or equal to #columns)**- Enter the matrix you want to reduce.
- Go to your home screen.
- Press
*MATRX*, cursor right to*MATH*, and select*B:rref*. - Call the matrix you want to reduce and hit
*ENTER*.

**Factorials**- Enter
*n*on your home screen. - Press
*MATH*, cursor over to*PRB*, and down to*4:!*. - Press
*ENTER*.

- Enter
**Permutations**- Enter
*n*on your home screen. - Press
*MATH*, cursor over to*PRB*, and down to*2:nPr*. - Enter
*r*. - Press
*ENTER*

- Enter
**Combinations**- Enter
*n*on your home screen. - Press
*MATH*, cursor over to*PRB*, and down to*3:nCr*. - Enter
*r*. - Press
*ENTER*

- Enter

**Histograms****Enter Data into Lists.**Your random variable(X) values should be entered into*L1*and the corresponding probabilities should be entered into*L2*.**Turn on Stat Plot.**Press*2nd Y=*and choose which plot you want. In class I used the first one. When on the Stat Plot screen, highlight the following options:On

Histogram (Bar Graph) picture - the last picture in the top row

Xlist: L1

Freq: L2

**NOTE: Once you've done this the plot will be turned ON until you turn it OFF.****Set Window.**Use X values to choose*Xmin*and*Xmax*. Set Y values between 0 and 1 and choose*Yscl*by looking at your data.**Graph.**(Make sure you don't have anything entered on*Y=*screen.)

**Expected Value/Standard Deviation/Variance**- Enter data into
*L1*and*L2*as in the above. - Press
*STAT*cursor right to*CALC*and down to*1: 1-Var Stats*. - When you see
**1-Var Stats**on your home screen, add*L1,L2*so that your screen reads**1-Var Stats L1,L2**and press*ENTER*. - The
**expected value**is the first number listed : x bar. - The
**standard deviation**is the fifth number listed: sigma x. - To find the
**variance**, use the standard deviation. Press*VARS*, cursor down to*5:Statistics*, and down again to*4:sigma x*. Then press the*x-squared*key and hit*ENTER*.

- Enter data into
**Binomial Distribution****Single Probability Calculation: binompdf()**-> Press*2nd VARS*and select option*0:binompdf*. The format of the command is as follows: binompdf(n,p,r), where n = the number of trials, p = the probability of success in each trial, and r = the desired number of successes.**This calculates P(X=r).****Cumulative Probability Calculation (Sum of Many): binomcdf()**-> Press*2nd VARS*and select option*A:binomcdf*. The format of the command is as follows: binomcdf(n,p,r), where n = the number of trials, p = the probability of success in each trial, and r = the desired number of successes.**This calculates P(0 <= X <= r).**

**Normal Distribution****P(a < Z < b) = normalcdf()**-> Press*2nd VARS*and select option*2:normalcdf*. The format of the command is as follows: normalcdf(left endpoint, right endpoint, mean, standard deviation).**P(Z < z)= a**- Press*2nd VARS*and select option*3:invNorm*. The format of the command is as follows: a = invNorm(probability, mean, standard deviation).

For both of these types of problems, go to

**Compound Interest**- Select option
*1:TVMSolver*. You should have the following on your screen:*N =*

*I%=*

*PV=*

*PMT=*

*FV=*

*P/Y=*

*C/Y=*

- If you are making payments, make sure that
*END*is highlighted at the bottom of the screen. - Fill in all but one of the above options (the one you are trying to solve for) as follows: N = the total number of times compounded
(the number of times compounded per year times the number of years), I% = interest rate (not in decimal form), PV = present value
(the amount you invest), PMT = value of payments (0 if you are not making any payments), FV = future value (the amount of money you have at
the end of your investment),
P/Y = the number of payments per year (the number of times compounded per year if you are not making any payments), C/Y = the number of times
compounded per year.
**If you fill in PV and FV, one must be negative in order for your calculator to find an answer.**(Simulating the flow of money between you and the bank.)**Make sure you have some kind of value entered in the spot for whichever variable you are solving for or else the calculator will not let you proceed to input values for the rest of the variables.** - Move your cursor to the value you are solving for and hit
*ALPHA*and then*ENTER*.

- Select option
**Effective Rates of Interest**- Select option
*C:Eff(*. - Input the nominal interest rate (not in decimal form) followed by a comma and then the number of times the account is compunded per year.
- Hit
*ENTER*.

- Select option