Cubic polynomial unable to be factored nicely

  • Thread starter Thread starter anniecvc
  • Start date Start date
  • Tags Tags
    Cubic Polynomial
AI Thread Summary
The cubic polynomial 6x^3 - 3x^2 + 12 cannot be factored nicely, as attempts using the rational roots theorem and synthetic division yielded no results. The polynomial can be partially factored to 3[x^2(2x-1) + 4], but further simplification does not lead to rational roots. Analysis with Wolfram shows one irrational and two complex roots, confirming its non-factorable nature. The consensus suggests that the problem may have been a typo in a past exam. Overall, this polynomial does not lend itself to straightforward factorization.
anniecvc
Messages
28
Reaction score
0
Found this on a test for an integrated algebra 2 high school math class!

Factor completely.

6x3 - 3x2 + 12

The Attempt at a Solution



3( 2x3 - x2 + 4) eq.1

At this point I checked for rational roots using the rational roots theorem and synthetically dividing. I got nothing.

Although this doesn't get us anywhere x2 can be factored out of the first two terms:

3[ x2(2x-1) +4)] eq. 2

I then plugged this guy into Wolfram and it is giving me 1 nasty irrational and 2 nasty complex roots. I'm convinced this is NOT "nicely" factorable. Does anyone have any insights?
 
Physics news on Phys.org
You're correct that it can't be factorized using the rational root theorem, so as such, I wouldn't go any further with it. Since it was in a past exam, I'm sure it was a typo that they ended up correcting for the students on the day.
 
Back
Top