Quantcast

A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

PhoenixFire

  • 2 years ago

Factoring a cubic polynomial. \[x^3-108x^2+3564x-34992\] I haven't needed to factor a cubic in a while and have forgotten how. Any help? I know the answers, just can't get them.

  • This Question is Closed
  1. Kitt020912
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I know how to factor, but explaining it to someone is complicated. I haven't factored in so long either. I'll try to explain it. Sorry if I'm no help.. :/

  2. maddyx
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    http://answers.yahoo.com/question/index?qid=20080417160912AAt8IHC This could help :)

  3. Kitt020912
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Sorry I can't help you. >_< I'm a failed Amby on my first day. :c

  4. drawar
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \[\begin{array}{l} {x^3} - 108{x^2} + 3564x - 34992 \\ = x({x^2} - 108x + 2916) + 648(x - 54) \\ = x{(x - 54)^2} + 648(x - 54) \\ = (x - 54)({x^2} - 54x + 648) \\ = (x - 54)(x - 36)(x - 18) \\ \end{array}\]

  5. Boblovesmath
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @drawar from where did you 2916?

  6. drawar
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    54^2

  7. Boblovesmath
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I know but it is not found in the original equation.

  8. drawar
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Yes but you have to bring it in, and subtract it later, that's the one and only trick when doing factorization of polynomials.

  9. Boblovesmath
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Where did you subtract it? And in which course did you take this?

  10. drawar
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    3564=2916+648

  11. drawar
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    I don't remember which course, I think it's common sense, no?

  12. Boblovesmath
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Can you please explain the before the last step? I don't get it, how did you reach to that point?

  13. Boblovesmath
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @drawar

  14. drawar
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Use a calculator to get 2 roots

  15. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.