# Top 10 Texas Instruments TI-84 Plus Calculator Questions & Answers

## Question

• 19,675 People Helped

### How do you enter a plus minus sign?

Title says it all.

Posted by on

to put X+-X is to use the "(-)" button and not the "--" button for a negative.

Posted on Feb 09, 2009

## Question

• 18,610 People Helped

### how do i use the inverse log operation on the TI-84

Hi,

I'm trying to calculate something for chemistry and the function I need to perform is the inverse log operation. To calculate the ph of a substance the formula is -log(value) but to calculate what i need to now I need to use an inverse log function and removing the - sign before the log key is not working. I have also tried the L1 function and it doesn't work either.

Thanks

Posted by on

The problem is simple. You're trying to get an [H+] concentration which is obviously going to have a value of some number times ten raised to a negative power. Therefore, you have to insert the negative value of the pH into the 10^(x). When you insert said negative number you will come out with the right answer.
i.e.
The pH of a sample of human blood was calculated to be 7.41. What is the [H+] concentration of the blood?
10^(-7.41) = [H+]
[H+] = 3.9 E-8
(the answer should only have two sig. figs because the pH has two digits after the decimal.

Posted on May 18, 2009

## Question

• 18,321 People Helped

### how do i check the

how do i check the battery life of the calculator?

Posted by on

The life of the batteries depend on the use. If calculator is on and running programs 24 hours a day, the batteries will not last more that 2 or 3 days. If you use it the calculator for 2 hours a day, fresh batteries may last a semester.
But I believe you want to check the CURRENT state of the batteries. You can buy from an electronic store or a dollar store a device that tells you if a battery is still good or not.
With the TI Connect software you can check battery status. See the screen capture that follows. To obtain the displayed window you must click the button DeviceInfo with calculator connected to the computer and TI Connect running.

Posted on Jul 17, 2011

## Question

• 18,161 People Helped

### where is the equal sign on the ti 84 plus

where is the equal sign on the ti 84 plus

Posted by on

hello sir, Press "second" "math", and it should be the first thing listed. If you need other commands hit "second" "0" that will enter the catalog and you can press any letter (without hitting alpha) to jump to that letter in the list. Please click on the following link to see the manual of the TI-84 Plus Calculator:
kindly rate me.. thanks for using fixya..

Posted on Mar 03, 2010

## Question

• 15,831 People Helped

### My TI-84 Plus won't graph two functions at once.

My TI-84 Plus won't graph two functions at once. Only one equal sign highlights. My math teacher doesn't even know what to do and I really need two functions to show on one graph.

Posted by on

Hello,
Turn the satistical plots OFF
Press [2nd][Y=] (STATPLOT). Select or enter 4: to execute the command [PlotsOff] [ENTER]

Clear the lists (statistical lists)
Press [2nd][0] (Catalog]. Press [PGRM] C. The cursor jumps to the first command in catalog that starts with C (The greek letters in names do not matter). Scroll down a bit to reach the command [ClrAllLists]. Select it and press [ENTER].

If you still have problems, just reset the RAM:
Press [2nd][+] (MEM). Press 7 to select [Reset] then [1:All Ram][2:Reset]. Press [Clear] to erase the Ram Cleard message.

Now you should be able to draw the graphs.

Hope it helps.
Thanks for using FixYa.

Posted on Nov 19, 2009

## Question

• 12,467 People Helped

### how do input subscripts into

how do input subscripts into a program with a TI-84 Plus? Like Y(sub 1)=y

Posted by on

Use the square brackets ("[" and "]"). They're the shifted functions of the multiply and subtract keys. For Y(sub 1) enter it as "Y[1]".

Posted on May 16, 2011

## Question

• 10,007 People Helped

### how do you use a plus or minus sign on a TI-84

how do you use a plus or minus sign when in y= mode on a TI-84 PLUS silver edition calculator?

Posted by on

Hi,
You cannot use the ± in the definition of a function. If you need to consider two alternatives, you have draw each function separately, one function as Y1 and the other as Y2. I just checked the catalog of commands, and there is no ±.

Hope it helps.
Thanks for using FixYa

Posted on Nov 19, 2009

## Question

• 9,909 People Helped

### TI 84 will not graph multiple functions simultaneously

I have had the TI84 for more than a year. Recently, it stopped graphing completely because somehow the PLOT 1 PLOT 2 PLOT 3 at the top of the function (Y =) screen were highlighted. Now I can get one fuction at a time....anyone know how to make the TI84 graph multiple functions simultaneously?

Already tried highlighting multiple functions (and only one equal sign will highlight at a time) and already reset Mode to SIMUL. Have also tried changing the line type at the far left of the function...no effect.

Posted by on

Turn off transformers. Go to apps and go all the way down until you reach transformers then hit enter. Then a menu should appear and hit uninstall that should fix it.

Posted on Sep 13, 2008

## Question

• 9,829 People Helped

### how do i put brackets

how do i put brackets in a problem

Posted by on

Use the parenthesis above the 8 and 9 keys. Don't use the curly braces on those shifted keys (those are for lists) nor the square brackets on the multiply and subract keys (those are for arrays).

Posted on Sep 16, 2010

## Question

• 9,797 People Helped

### How do I put cosecant, secant, and cotangent

How do I put cosecant, secant, and cotangent functions into my ti-84 plus?

Posted by on

By definition

1. cosecant of X =1/sin(X), must not be confused with arc sine [sin^-1]
2. secant of X =1/cos(X), must not be confused with arc cosine [cos^-1]
3. cotangent of X =1/tan(X), must not be confused with arc tangent [tan^-1]
Because of these simple relations, calculator makers do not implement them with specific key sequences.
On this calculator, you have two ways to calculate one of these functions. EX cosecant of 37 degrees
1. You enter 1 / [sin] 37 [ ) ] [ENTER] result is 1.661640141
2. You enter [sin] [ ) ] 37 [ENTER] followed by [X^-1] to take the reciprocal of the previous answer. The [X^-1] key is the one just below [MATH].
A word of caution: secant cosecant and cotangent must not be confused with the inverse trigonometric functions arcsin, arccos, arctan

Posted on Jan 21, 2010

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