I just got my sister's TI-89 calculator and I don't know how to use it. I'm trying to find out how to graph a non-linear inequality. Any ideas?

The solution set of a linear inequality in two variables (x,y) is one half of the Cartesian plane. The half-plane may or may not contain the boundary line defined by the = sign. Thus it is expected that the calculator shades the relevant half-plane. If you are dealing with nonlinear inequalities the calculator shades inside or outside the curve.
When drawing multiple inequalities the Casio offers you the possibility to shade the regions where ALL conditions (ALL inequalities) are simultaneously satisfied. The other option is OR.
If you are not interested in the shading do not draw inequalities, draw equations (with =).

You have to use Y Editor to define functions on the both sides of the equation and then graph it. Finally option is F5: Intersection.
See captured images for equation 5x+10=-2x-7, y1=5x+10, y2=-2x-7 and x=-17/7

One of the applications Inequalz or Transfrm is still loaded in memory and it controls the graphing capabilities of the calculator. To restore control to the naative OS, proceed as follows.
Press the APPS button.
Scroll dowwn or Up to find Inequalz.
Select it and press ENTER.
A message is displayed sayin Inequal Running.
Select 2:Quit Inequal.

If the message you get is
APP CONFICT.
or Conflicting Apps
Reset the RAM to kick the applications out of memory

You don't need an app. Just press the Y= button and enter the inequality as if you're entering another function to be graphed. Then press left-arrow repeatedly to move to the diagonal line at the left end of the display. Press ENTER repeatedly to cycle through the different graph styles. If the inequality is of the form "y less than" or "y less than or equal to", select the shaded triangle below the line. If the inequality is of the form "y greater than" or "y greater than or equal to", select the shaded triangle above the line.

If you want to graph the absolute value of a function, feed the function to the absolute value ie graph y= abs(f(x)). The calculator will take care of it. See screen captures where I draw the function y1=x^3-5x^2-3 and y2='x^3-5x^2-3'. On the first graph the function is represented and on the second the function and its absolute value.







The calculator knows how to calculate the absolute value of an expression. The name of the command is abs(

i do not think it can

Sorry, but you cannot calculate limits of functions with this calculator. It does not have a Computer `Algebra System (CAS). For that you need a graphing calculator with CAS: Casio ClassPad 300, 300PLUS, 330, HP 48 GII, HP49 G/ G+, HP 50G, TI-NSPIRE CAS, TI89 Titanium, TI 92/92PLUS, TI Voyage 200 PLT. It is still a very good scientific (non graphing) calculator
However, you can calculate numerical derivatives, and numerical integrals, solve linear and non-linear equations.

Even though this post does meet your expectations, do not let that prevent you from rating it.

Hi,
You are running the application called Inequalz. It can be used to plot inequality graphs. You must uninstall it (NOT DELETE) to return to the normal calculator configuration.
Press [APPS]. Scroll down to find Inequalz. Highlight its number in the list and press {ENTER]. You will see a screen Inequal Running and

1. Continue
2. Quit Inequal
3. 3:About.

Press [2:Quit ..]
Your calculator will unload it out of memory.
Reset the RAM and restart the graphs.

Hope it helps.

Hello,
To enter the inequation you split it into two inequalities

Graph is as follows

Use [2nd][CATALOG] to access the relaional operators less than or equal, greater than or equal, and the operator AND.
To access the inequality signs scroll upwards from abs( to reach the bottom of the catalog.
Note: You can use t as variable only in parametric graphs. Use x.
Hope it helps.

Hello,
I have no idea what you are thinking about when you say models, but to graph ANY function, you go to the home folder, and press the yellow [Diamond][Y=] and enter the functions at the = signs.


When finished entering functions, press the yellow [Diamond] key then [GRAPH]. Here is what you get. The straight line is a linear function (y=2X +3.


Hope it helps.