1. Enter your function into Y=.
2. Return to the home screen by pressing 2nd MODE(QUIT).
3. Call your function to the home screen by pressing VARS, cursoring right to Y-VARS, selecting 1:Function, and choosing the appropriate function name.
4. You will now have your function name on the screen, say Y₁.
5. Add parenthesis and an x-value, just as function notation would be written on paper, so that you have something like Y₁(2).

1. Graph the two functions by entering the slope-intercept form of the lines into Y1 and Y2. These are located under the Y= button.
2. Click on GRAPH and make sure your window is set properly, making sure you can see the intersection on the graph. If not, adjust the WINDOW to include the region of the graph where the lines intersect.
3. Go to CALC which is found by pressing 2nd TRACE.
4. Select option 5:intersect.
5. 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.
6. 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.
7. The intersection point will appear at the bottom of the screen.

• Using Intersections
  1. Put your quadratic function into Y1 and set Y2=0. (You can use any two function locations.)
  2. Find the intersection points of these two functions using the directions given above.
  
  
• Using the Zero Function
  1. Put your quadratic function into Y1 (or any other function location).
  2. Graph the function so that you can see where the quadratic crosses the x-axis (where your function = 0).
  3. Go to CALC which is found by pressing 2nd TRACE.
  4. Select option 2:zero.
  5. The calculator will prompt you for the Left Bound. Use your left or right arrow key to move the cursor to the left of where it crosses and hit ENTER. The calculator will then prompt you for the Right Bound. Move the cursor to the right of where it crosses and hit ENTER.
  6. The zero will appear at the bottom of the screen.   x = C       y=0
     The x-intersect is the value of the constant C above.

• Linear Regression
  1. 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.
  2. 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!) 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

  3. Now, press ENTER. The following should appear on your screen:

     LinReg(ax+b)
     y = ax+b
     a =....
     b =....
     r² =....
     r =....
     

     Your regression line is the equation now saved under Y1. If you don't have the r or r², 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 twice , and it should say Done.
  4. 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.
  5. To find a y value from your regression line when given an x value, go to CALC (2nd TRACE) and select option 1:value. Then just enter the value for x.
  6. 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.
  
  
• Other Models of Regression
  
  Follow the instructions in step 1 of linear regression above for inputting the data and then select the following options under STAT → CALC to find the specified models. If you would like to plot the equation with your data or predict values from your model, follow the instructions in steps 4-6 given above for linear regression.
  
  • Quadratic Regression:      5:QuadReg
  • Exponential Regression:   0:ExpReg
  • Power Regression:            A:PwrReg
  • Cubic Regression:             6:CubicReg
  • Quartic Regression:          7:QuartReg
  • Logarithmic Regression:   9:LnReg
  • Logistic Regression:          B:Logistic

• Compound Interest
  1. Select option 1:TVMSolver. You should have the following on your screen:

     N =
     I%=
     PV=
     PMT=
     FV=
     P/Y=
     C/Y=
     

  2. 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 in one year × the number of years),
     I% = interest rate (not in decimal form),
     PV = present value (the amount you invest),
     PMT = 0 (we are not making payments in this class),
     FV = future value (the amount of money you have at the end of your investment),
     P/Y = C/Y = the number of times compounded per year (since we are not making payments).

     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.

  3. Move your cursor to the value you are solving for and hit ALPHA and then ENTER.
  
  
• Effective Rates of Interest
  1. Select option C:Eff(.
  2. 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.
  3. Hit ENTER.

1. Go to MATH and select option 9:fnInt.
2. Fill in the four arguments for fnInt as follows: fnInt (function, X, lower limit, upper limit)
      ie:  fnInt(Y1,x,-2,5) or fnInt(x²-4x+9,x,-8,2)
3. Hit ENTER.

Edited: 6/1/06 md