Why Doesn't My TI-89 Solve Inequalities Correctly?

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SUMMARY

The TI-89 calculator does not inherently solve inequalities, as confirmed by multiple users in the discussion. Users reported that entering inequalities like x^2<1 results in the calculator returning the inequality itself, rather than a solution. However, the TI-89 Titanium model has been noted to solve inequalities correctly, indicating a potential upgrade in its Computer Algebra System (CAS). For accurate results, users should clear variables and consider separating inequalities into distinct equations.

PREREQUISITES
  • Understanding of TI-89 calculator functionalities
  • Familiarity with solving inequalities in algebra
  • Knowledge of the Computer Algebra System (CAS) in calculators
  • Experience with variable management in TI-89
NEXT STEPS
  • Research the differences between TI-89 and TI-89 Titanium functionalities
  • Learn how to clear variables on the TI-89
  • Explore methods for solving inequalities using separate equations
  • Investigate updates and features of the TI-89 Titanium's CAS
USEFUL FOR

Students, educators, and anyone using the TI-89 or TI-89 Titanium calculators who require assistance with solving inequalities effectively.

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I'm having some trouble solving inequalities with the TI-89. Let's say that I want to solve x^2&lt;1 The answer should be &lt;-1,1&gt;, if I type in solve(x^2<1,x), but that's not what I get. It only returns the inequality itself just as I typed in. What's wrong??
 
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i will have to check the set up but if its all entered correctly make sure you clear your varables so you don't have x stored as something
 
I don't think that the TI-89 will solve inequality equations. You'll have to separate the inequality into two separate equations and solve them separately.

If the TI-89 does have this function, I am unaware. Just checking my manual it doesn't look like it.
 
TI 89 is pretty complicated. I had a similar problem and a Person I know that works a t Texas Instrument Company that makes calculators claims it doesn't do inequalities and is a ripoff for what it seems. aerognr is right.good Luck though!:)
 
This is quite surprising to me because I have a TI-89 Titanium and it can easily solve inequalities. Writing your original query I got: -1<x<1. I was under the impression that the CAS was identical, but apparently they upgraded it.
 
try :

solve(sign(factor(x^2-1))=-1,x)
 

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