Question about Texas Instruments TI-89 Calculator

# My TI-89 Titanium won't graph sin, cos, or tan?

Posted by on

• kakima Nov 10, 2010

Do you have the proper angular mode set? If your calculator is set to degrees and the window range is set to its default, the sine and tangent are virtually zero and the cosine is one.

×

• Level 2:

An expert who has achieved level 2 by getting 100 points

All-Star:

An expert that got 10 achievements.

MVP:

An expert that got 5 achievements.

Sergeant:

An expert that has over 500 points.

• Texas Instru... Expert

See example for y=sin x

Posted on Mar 08, 2012

Hi,
A 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
The service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
Good luck!

Posted on Jan 02, 2017

SOURCE: SIN COS TAN

The answer that you have received in actuality is correct. However, it is in exact form when the answer that you were looking for was an approximation (decimal form) answer. To achieve this all you have to do is hit the alpha button (the yellow button with a diamond in the center) and then enter which will give you your desired answer :-)

Posted on Jan 15, 2008

for function = (sin,cos,tan,sec,cosec,cotan)
arc(function) = function^-1, calculated in the first quadrant for simplicity(0-pi/2) (0-90deg), as all functions repeat circularly
just another method of notation

http://www.mathwords.com/t/tangent_inverse.htm

Posted on Jun 21, 2008

make sure it's in the right mode, i.e. radians, degress. check it under set up

Posted on May 21, 2007

To put it in Scientific mode, press MODE then use your right arrow to move your cursor one spot to SCI. Press ENTER then press CLEAR.

Posted on Jun 16, 2009

What is so surprising? The sine and cosine functions have ranges that span the closed interval [-1,1]. As to the tangent function, its range is the the whole real line.

This being said, you should keep in mind that there are three angle units: the degree, the radian, and the grad.
When you want to calculate the sine, cosine, or tangent of a number, that number is not just a number. It is an angle, and as an angle it has a unit.

For this reason a calculator generally has two angle units defined (degree and radian), and possibly the grad. BEFORE calculating any trigonometric function you must ascertain that the angle is in the correct unit.

Clearly, in the problem you are trying to solve angle values are given in degrees, but your calculator is configured to interpret angles values in radians.

To set the default angle unit to degree press [MODE] , then press down arrow twice to reach the line (radian, degree). Highlight the word degree and press [ENTER] to set the default angle unit to degree.

Unfortunately the TI 8xPLUS family of calculators does not have a status bar on screen to remind you of the modes, and if you do not remember to check the current unit you get errors (at least unexpected results).

However, there is a way to avoid the errors and that is to enter the unit explicitly after the angle value. To do that you press [2nd][APPS] to open the (ANGLE) menu list. Try it.

1. First item in list is the degree symbol, a raised 0
2. 2nd is the minute, an apostrophe
3. 3rd is radian, a raised r
By selecting the degree symbol and pressing [ENTER}, that symbol echoes on the screen just after the angle value. Closing the right parenthesis of the trigonometric function and pressing [ENTER] will give you the result in the correct unit of your choice. This can be done regardless of the default unit the calculator is configured for.

Posted on Jan 21, 2010

×

my-video-file.mp4

×

## Related Questions:

### How do you graph this equation r(t)=cos(t) * i + sin(t)* j + t *k (x,y,z)= (i,j,k) on a ti89

The calculator does not support 3D parametric functions, but there is a procedure that will help you do that. Here is the link to the page that describes it.

Jun 12, 2012 | Texas Instruments TI-89 Graphing Calc...

### Will not graph sin/cos/tan properly

Make sure you have the angular mode set to radians. In degree, the graph of sine(x) is nearly a straight line for small values of x.

May 08, 2012 | Texas Instruments TI-Nspire CAS Graphing...

### TI89 is giving wrong answer for the integral of sec(x). Please help. It gives the answer as: ln[ |cos(x) / (sin(x)-1)| ] when it should be ln[ |(sin(x)-1) / cos(x)| ]. Why is it giving the wrong...

Hi danagasta,

If my last instructions did not work then you need to reset your RAM. You are missing the negative sign and, I have no idea where you got the absolute value inside the brackets.
Yes, the absolute value are used in books and, on integral tables but, I can asure you that the Ti 89 should not have produce them in this answer.

I'll stand behind that In( -cos(x) / (sin(x)-1)) is the correct answer. You can go ahead and simplify after the calculation to get the answer you want but, that is the good answer that Ti 89 is going to give you for the integral of sec(x).

Errors that do not match the suspected, I am pretty sure that Texas Instruments would have you clear the RAM. I do not like resetting the RAM but, I could not find the cause to why you got the answer you did. And so far no other expert has produced a solution to convince me otherwise.

I was not able to come up with any of the 3 answers MiB8888 did on my Ti 89. I am not saying that they are not good answers, they are book and integral tables answers. You are not going to get them on the Ti 89.

Jan 04, 2011 | Texas Instruments TI-89 Calculator

### All trig-based graphs give me weird results on my TI-89 Titanium. Taking y=sin(x) for instance, I get a clean diagonal line through the point (0,0), almost resembling the graph y=x with window xmin = -10...

You have your angular mode set to degrees. Ten degrees is about 0.17 radians, and for small x: sin(x) is nearly equal to x. Thus, sin(x) from -10 to 10 is indeed nearly a straight diagonal line.

Press MODE, then scroll down to "Angle" to change the angular mode.

Jun 03, 2010 | Texas Instruments TI-89 Calculator

### Tan Cos and Sin errors

go to:

mode
select DEGREE rather than RADIAN three lines down.

Aug 20, 2008 | Texas Instruments TI-84 Plus Silver...

### TI-84 Plus silver edition sin/cos/tan

for function = (sin,cos,tan,sec,cosec,cotan)
arc(function) = function^-1, calculated in the first quadrant for simplicity(0-pi/2) (0-90deg), as all functions repeat circularly
just another method of notation

http://www.mathwords.com/t/tangent_inverse.htm

Jun 19, 2008 | Texas Instruments TI-84 Plus Silver...

### Cosh Squared or Cubed

if you want to square sin(3), press:

(
sin
3
)
)
^
2

Sep 24, 2007 | Texas Instruments TI-89 Calculator

### TI-89 Problems

There isn't anything "wrong" with it.

Go to mode, and set the results of your inquiries from Exact to approx.

If you put in cos(e^2), it will print out cos(e^2) because it's the most exact it can be without going into a decimal. (cos(e^2) will be a transcendental number like Pi).

Sep 09, 2007 | Texas Instruments TI-89 Calculator

## Open Questions:

#### Related Topics:

770 people viewed this question

Level 3 Expert

Level 2 Expert