![]() |
We start in Figure 1 with the result of using the
key sequence ![]() ![]() |
![]() | The polynomial equation that we want to solve is
![]() We finish this screen and move to Figure
3 via the |
![]() | The calculator responds by showing us a
standard, second order polynomial equation, namely
|
![]() | Our equation is
|
![]() | In Figure 4 we gave the calculator the values for the numeric
coefficients. Now we press the ![]() |
The first five screens here show the use of the POLY key function. In Figure 5 we saw the answers for our problem. Note that the answers may need to be converted to fractional format, but this is going to be difficult with the keyboard version of the poly command.
The following three screens repeat our solution, but with the poly command. The poly command needs to be followed by a list represnting the coefficients of a polynomial. The number of items in the list determines the order of the polynomial equation. Note that it takes three items in the list to represent all three numeric coefficients in a second order polynomial equation.
![]() | To create Figure 6 we have merely typed out the entire command.
The keys ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
![]() | Having constructed the command in Figure 6, we need only press the
![]() |
![]() | One of the advantages of having the "list" of solutions is that we can
obtain the values in fractional format. In Figure 8 we have
used the ![]() ![]() ![]() ![]() ![]() ![]() |
![]() | In order to put the "poly" command into the CUSTOM menu we first
need to find it in the CATALOG. We do this by openning the CATALOG menu via
the ![]() ![]() |
![]() | We move forward by pressing the ![]() ![]() |
![]() | Either the cursor down key, ![]() ![]() ![]() We note in Figure 11 that there are open spots in the CUSTOM menu.
We will place the "poly" command into the second
spot by pressing the |
![]() | Figure 12 shows us that we have placed the "poly" command into the
second slot of the CUSTOM menu. We use the ![]() |
![]() | Having left the CATALOG menu from Figure 12, we can open the CUSTOM
menu in Figure 13 by pressing the ![]() ![]() |
![]() | Figure 14 shows the calculator display after we have
completed entering the values for the equation
|
![]() | We can change the answer to fractional form via the
![]() ![]() ![]() ![]() ![]() |
![]() | In Figure 16 we are attempting to find the solutions for
|
![]() | Naturally, we can use the ![]() |
![]() | Now we will look at the solution to the equation
|
![]() | The display for Figure 19 shows the rest of the answer from Figure 18. |
![]() | For Figure 20 we have started the the QUAD program. (More information
on the QUAD program for the TI-86 and TI-85 can be
found on the 208606.htm page.)
We have entered the values for the coefficients. We still need to
press the ![]() |
![]() | The QUAD program calculates the discriminant and, recognizing that the discriminant is negaitve, that program merely tells us that there is no real solution. |
![]() | QUAD1 is a more elaborate program. (More information on the QUAD1 program can be found on the 208607.htm page.) In Figure 22 we have started that program and entered the values into it. |
![]() | Again the result is that there are no real solutions. |
![]() | Figure 24 has the start of the QUAD2 program. (More information on the QUAD2 program can be found on the 208608.htm page.) Again we have entered the coefficients. |
![]() | Unlike the earlier programs, QUAD2 is happy to process quadratic equations that have complex number solutions. In Figure 25 we see those two solutions, not as decimal approximations, as in Figures 18 and 19, but as complex numbers, including the square root of 39. |
PRECALCULUS: College Algebra and Trigonometry
© 2000 Dennis Bila, James Egan, Roger Palay