# Top 10 Texas Instruments TI-86 Calculator Questions & Answers

## Question

• 27,165 People Helped

### HOW TO FIND CUBE ROOT

I need help on how to use my calculator to find the cube root of something. How do i do it on my calculator??

Posted by on

There is a way to do it. I believe you go into "complex" or "math" buttons. These buttons are yellow on the calculator. Therefore, to access them you must hit "2nd" then the button.

Better yet, you can also get around this dilemma another way. You can enter "the cubed root of x" by raising x to 1/3.

For example the cubed root of x = x^(1/3). It is best to place parentheses around 1/3 so the calculator knows exactly what you mean.

Another example, the "cubed root of (x + 1)" can be entered by:
(x+1)^(1/3) Note the parenteses around both (x+1) and (1/3). This applies if the radical cover both "x" and "1".

Hope this helps.

Posted on Nov 09, 2007

## Question

• 10,076 People Helped

### texas instruments ti-86 screen problem

Recently, I've used my old ti-86 and I saw too many lines across the screen that cut off the numbers appear on the srceen. How to fix that problem?

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The TI-86 uses a very small, very thin ribbon cable to connect the display board to the LCD. The cable is about 2.5 " wide and about 4" long, and is only slightly thicker than a piece of paper but has about 40+ leads buried inside. Over time the leads will break at the folds (there are at least two folds in this cable to fit it down inside the case). There is no cheap solution to fix this problem. You might have some "Mr. Fix-it" try to fix it, but he will tell you to throw it away after he renders it completely inoperable. The calculator uses two Torx bit screws at the bottom of the case (T-6 size) so you will have to get the correct screwdriver to open the case. Save your money, sanity and time and use it till you can't stand the missing lines and throw it out. Even the data cable looks like it is glued down so if it lifts off after being cooked or frozen a couple of dozen times in the back of your car you can't fix this.

Posted on Jan 20, 2010

## Question

• 5,948 People Helped

### getting the Error 13 Dimension

When I try to graph an equation I get the Error 13 Dimension. I just replaced the batteries, but I'm not sure where I have to fix the problem.

Posted by on

This just happened to me too after i tried to plot some statistics. Press 2nd, +(STAT), then F3 for plot and see that you have all the STAT PLOTS turned off.

Posted on Oct 28, 2008

## Question

• 4,227 People Helped

### How do you use the imaginary number with the TI-84 calculator?

example problem: finding the solution to a radical (square root of a negative number) using i.

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If you want the answer in rectangular form, set MODE a+bi and tap ENTER and QUIT. Tap square root sign, tap (-)4 and close the parenthesis and tap ENTER. The answer is shown as 2i.
If you want the answer in polar form, set MODE to re^xi and and DEGREE. Tap ENTER and QUIT. Tap the square root sign, tap (-)4, close the parenthesis, and tap ENTER. The answer shown is 2e^90i. (2 at ninety degrees). If you selected RADIAN mode, the answer would be 2e^1.57i (2 at 1.57 radians; or 2 at pi/2 radians)

Posted on Dec 20, 2009

## Question

• 3,622 People Helped

### how do I find the cube root button on my TI- 86

how do I find the cube root button on my TI- 86

Posted by on

Hello,
There is a relation between roots and fractionary powers.

2nd root (square root) of X = X^(1/2) power 1/2
3rd root (cubic root) of X = X^(1/3) power 1/3
4th root of X = X^(1/4)
...
n-th root of X = X^(1/n)

Use the raise to arbitrary power key labeled as a caret [^] or [X to the y] or [Y to the x]
Hope it helps.

Posted on Oct 12, 2009

## Question

• 3,275 People Helped

### how do i enter cube root on the ti86

how do i enter cube root on the ti86

Posted by on

In the MATH MISC menu you'll find the xth-root function. Use this to find the 3rd root.

3 xth-root 8 ENTER will give 2.

Posted on Sep 13, 2010

## Question

• 3,197 People Helped

### Hos do I adjust the screen brightness?

Hos do I adjust the screen brightness?

Posted by on

Press and release the 2nd key and then press the up-arrow to darken or the down-arrow to lighten. Repeat as needed.

Posted on Sep 21, 2012

## Question

• 2,982 People Helped

### 180% as a fraction in simlest form

turn 180% into a fraction in simplest form

Posted by on

Hello
180%= 180/100=18/10=9/5

Posted on Nov 13, 2009

## Question

• 2,611 People Helped

### TI 86- Texas instrument

Screen is black, unable to see anything. I tried to push some buttons but the screen is still black.

Posted by on

OMG THANK YOU SOOO SOOO MUCH

i had borred my friends ti-86 and when school finished i forgot to return it. i ended up leaving the calculator in my car where the sun fried the battery.
3 months later i brought new batteries and when it turned on i only saw black and i started to freak out thinking i had to buy a new one..

ONCE again thanks for the solution

Posted on Aug 26, 2008

## Question

• 2,487 People Helped

### Blank lines across the screen of a TI-86 graphing calculator

I have a TI-86 graphing calculator and I have had it for quite a few years. I turned it on after not using it for a while and just put in new batteries, but now it has blank lines across the screen. It looks to me like it just has dead pixels from being so old, but I was wondering if there is anything I can do to fix it or would I have to buy a whole new calculator?

Posted by on

Try this, hook up new battery and go to MODE and darken and lighten the screen.. do it ten to fifteen times. if that doesn't help, try hook up most left and most right's battery terminal to a DC supply at 4.5V. dont go above 4.5 it will fry your calc (it is design to handle 3V). now you are forcing extra juice into the dead LCD screen lines... and reapeat the MODE + darken trick. I fixed mine like that! Works! and remeber to leave it completely black(darkest) for a while to keep that dead line alive!

Posted on May 07, 2011

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