Solving Rational Inequalities: How to Find the Solution Set?

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Homework Help Overview

The discussion revolves around solving a rational inequality involving the expression (x^2 + 3x + 2) / (x^2 - 9) < 0. Participants are exploring methods to find the solution set and the implications of critical values and intervals.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to factor the expression and expresses confusion about how to proceed after identifying critical values. They question the possibility of solving the inequality using cases based on vertical asymptotes.
  • Some participants mention using sign charts to analyze the inequality and suggest checking values within the identified intervals.
  • There is a discussion about the appropriateness of the original poster's approach and the rules regarding thread management.

Discussion Status

The conversation is ongoing, with participants offering different methods and questioning the original poster's understanding of the topic. There is no explicit consensus on the best approach, but some guidance regarding checking intervals has been provided.

Contextual Notes

The original poster indicates a lack of understanding due to missing a lesson, which may affect their grasp of the concepts involved in solving rational inequalities.

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Homework Statement



x^2 +3x +2
__________ < 0
x^2-9



Homework Equations





The Attempt at a Solution



I factored the top to be

(x+2) (x+1)
______________ < 0
(x-3)(x+3)

Couldnt cancel anything out, So now i don't know what to do. I missed this lesson in class and i don't really understand wtf I am supposed to do. Inequalities usually have 1-3 cases in which we solve for x and create a therefore statement in, however, how am i supposed to solve this?

In the book it just shows intervals, but is it possible to solve through 3 cases as wel? ie)
x < -3 , x > 3 (since those are the vertical asymptotes)
 
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anyone?
 
I use sign charts to solve rational inequalities. See http://www.purplemath.com/modules/ineqsolv3.htm" for an example.

P.S. Why do you continue to bump your thread before waiting 24 hours? It's against the rules, so I've reported you to the mods.
 
Last edited by a moderator:
Cuz i dun got 24 hours to wait for a small response. nt tho kid gl
 
(x+2) (x+1)
______________ < 0
(x-3)(x+3)

The critical values of x of {+3, -3} at which the rational expression is undefined, and the critical values of x of {-2, -1} at which the rational expression is zero, contain the the values which break the Real Numbers into intervals which you can check.

You then can check any value within EACH of the intervals of the Real Numbers to determine if the value makes the inequality true or false. The intervals to check are obviously (-∞, -3), (-3, -2), (-2, -1), (-1, +3), and {+3, ∞).
 
eumyang said:
P.S. Why do you continue to bump your thread before waiting 24 hours? It's against the rules, so I've reported you to the mods.
Report noted, and acted on.
 
Nelo said:
Cuz i dun got 24 hours to wait for a small response. nt tho kid gl
Knock off the childish text speak and type in normal English.
 
Nelo said:

Homework Statement



x^2 +3x +2
__________ < 0
x^2-9



Homework Equations





The Attempt at a Solution



I factored the top to be

(x+2) (x+1)
______________ < 0
(x-3)(x+3)

Couldnt cancel anything out, So now i don't know what to do. I missed this lesson in class and i don't really understand wtf I am supposed to do. Inequalities usually have 1-3 cases in which we solve for x and create a therefore statement in, however, how am i supposed to solve this?

In the book it just shows intervals, but is it possible to solve through 3 cases as wel? ie)
x < -3 , x > 3 (since those are the vertical asymptotes)
Copy.
 

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