My ti-89 gives me a data type error when I am asking for rref on the matrix that I entered.

SOURCE: My TI-89 cant do simple calculations.

You have to set how the calculator handles numbers. To do this follow these steps: 1. Press the 'MODE' button. This brings up the calculator's main settings page. 2. Scroll down until you reach a field titled 'Exact/Approx...'. This is the setting for how the calculator handles numbers, whether it will show the exact answer (which is usually in fraction format) or whether it will show an approximate number (which will be in decimal format). 3. Press the right arrow which will bring up the options for that setting. You must now choose between three ways of handling numbers: -'1:AUTO' will determine which type of answer the calculator will give based on what numbers you want it to calculate (e.g. if you want an answer in decimal format just add a decimal somewhere in your problem). -'2:EXACT' will automatically display all answers in either whole number format or in fraction format. -'3:APPROXIMATE' will automatically display all answers in decimal format. 4. After you have selected one of those options press enter one more time to get out of the 'MODE' dialogue and return to the 'HOME' screen. Now try a problem and see what happens. Personally I like using 'AUTO' because then I don't have to keep returning to 'MODE' when I want either or. Hope this helped, I had the same problem when I first started using the TI-89.

SOURCE: "domain error" message on ti-89 titanium

I had the same problem, this worked for me:

Mode -> page 2 -> Exact/Approx change from "Exact" -> "Auto"

SOURCE: Calculating out npv and irr

Use the "FINANCE" app:

[APPS] [1] [ENTER]

for npv: select "7:NPV"
now you should get "npv(" on your screen.
use: npv(interest rate, cost {cash flows}, {frequencies of cash flows})


for irr: select "8: irr"
"irr(" will come up.
use: irr(interest rate, cost {cash flows}, {frequencies of cash flows})

onomou

• 24 Answers
• Posted on Oct 03, 2009

SOURCE: steps in solving matrix on my ti 89 calculator.

I assume you are speaking of solving a system of equations with a number of unknowns. If not, please correct me. Here's an example in practice:

If you have a system of 3 equations with 3 unknowns, you would set up your matrix so that the coefficients of each variable for a particular equation are on one row. So, given equations x + y + z = 0, 2x + 3y - 4z = 1, x + -z = -1 you would type the following into your calculator: [[1,1,1,0][2,3,-4,1][1,0,-1,-1]] and press enter to make sure you typed it correctly. notice that in the third row there is a zero, since we have zero time y for the third equation. Then row-reduce the matrix (2nd > 5 > 4 > 4 or in the CATALOG as rref). You should get out the matrix [[1,0,0,-1][0,1,0,1][0,0,1,0]]. This says that x=-1 y = 1 z=0 since my first column contained the coefficients for the x variable, the second for the y variable, and the third for the z variable. The last column contains the solution, the part on the other side of the equals sign.

Hope this helps! For more reading (from someone else; I just made this one up), check out the Wikipedia articles on Gaussian elimination and Systems of linear equations

SOURCE: My TI-89 won't convert temperatures.

Hi,
There is nothing wrong. For all units except temperatures you use the [|=>] the arrow operator to convert from one to anther. For temperature conversions however, you must use the tmpCnv( command.

Exemple of syntax. tmpCnv( is accessed through the catalaog or enter using the Alpha_shifted keys (Ti89)

tmpCnv( 100_ deg C,_ deg F) [ENTER] should give 212
You should explicitly enter the underscores, the degree symbols and the C, and F. The last two need not be capital letters).

Hope it helps.