Solving Polynomials on a TI-89 Calculator

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  • Thread starter Thread starter Motox7
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    Polynomials
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Discussion Overview

The discussion revolves around how to divide polynomials using a TI-89 calculator, specifically focusing on the input format for the expression 9x^5-6x^3+x-63 divided by x-8. Participants share their experiences and suggestions regarding the calculator's functionality and alternative methods for polynomial division.

Discussion Character

  • Technical explanation
  • Homework-related
  • Debate/contested

Main Points Raised

  • One participant expresses frustration with entering the polynomial division into the calculator and notes discrepancies in results compared to their teacher.
  • Another suggests entering the expression as (9x^5-6x^3+x-63)/(x-8) for correct evaluation.
  • A third participant recommends using the propFrac() function found in the algebra menu of the calculator.
  • Some participants advocate for synthetic division as a quicker alternative to using the calculator, highlighting its efficiency.
  • Concerns are raised about the order of operations affecting the input, with one participant clarifying how the expression might be misinterpreted by the calculator.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the best method for dividing polynomials, with differing opinions on using the calculator versus synthetic division. There is also uncertainty regarding the correct input format for the calculator.

Contextual Notes

Some participants note that the calculator may treat the expression incorrectly due to order of operations, which could lead to different results. The discussion reflects varying levels of familiarity with the TI-89's functions and the potential for misunderstanding its input requirements.

Who May Find This Useful

This discussion may be useful for students learning polynomial division, particularly those using a TI-89 calculator, as well as educators seeking to understand common challenges faced by students in this area.

Motox7
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okay, so i know how to factor( and the expand(

but i have a question for dividing polynomials such as...

9x^5-6x^3+x-63 / x-8

how do i enter this into my calculatoor?! AHH its driving me INSANEEEEEEEEEe

i get 9x^5-6x^3+x-63/x-8 but my teacher gets a different everytime for every problem similar to this...ahhh.

what do i dooooooo
 
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Enter it into your calculator as (9x^5-6x^3+x-63)/(x-8), but you could always just do the division yourself instead of on your calculator.
 
Personally I think it is easier and quicker to synthetically divide then to waste my time plugging it into a calculator.

If you don't know what synthetic division is, you can read about it at the bottom of this page.

http://www.purplemath.com/modules/remaindr.htm
 
ranger: Use propFrac() located in the algebra menu.


The TI-89 is often difficult (awkward) to use. The problem here is that 8 is not a root of the polynomial. Ranger hit the nail on the head. As for the Algebra menu, it's sort of hidden under the Math menu being the ninth function.
 
Motox7 said:
okay, so i know how to factor( and the expand(

but i have a question for dividing polynomials such as...

9x^5-6x^3+x-63 / x-8

how do i enter this into my calculatoor?! AHH its driving me INSANEEEEEEEEEe

i get 9x^5-6x^3+x-63/x-8 but my teacher gets a different everytime for every problem similar to this...ahhh.

what do i dooooooo

The problem is with the order of operations:

9x^5-6x^3+x-63 / x-8

gets treated as:

9x^5-6x^3+x- (63/x) -8

Presumably you meant (9x^5-6x^3+x-63)/(x-8); as d_leet suggested, enter it exactly in this form.
 

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