Quantcast

A community for students. Sign up today!

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

burhan101

  • one year ago

x intercept for this function

  • This Question is Closed
  1. burhan101
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\huge y=x^3-9x^2+15x+4\]

  2. burhan101
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    this is unfactorable?

  3. timo86m
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh no wait nevermind

  4. SmoothMath
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Any particular method they want you to use? Do they specify factoring?

  5. burhan101
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    No but isnt that the only way?

  6. SmoothMath
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Graphing is the easiest.

  7. SmoothMath
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Graph that bad boy. Look for where it crosses the x axis. Doneso.

  8. burhan101
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    no i have to use an algebraic method

  9. burhan101
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    because like say on an exam, i cant graph that

  10. Mertsj
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Possible rational roots are :

  11. SmoothMath
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Okay then your best best is to use the rational root theorem to list possible rational roots. Then check each one to see if it is a valid root.

  12. Mertsj
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\pm1,\pm4,\pm2\]

  13. Mertsj
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Use synthetic division to see if any of those are actual roots.

  14. SmoothMath
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Mertsj is correct. The way he got those possible roots is: A: Make a list of factors for the last number (In this case, it's 4) B: Make a list of factors for the first coefficient (In this case, it's 1) Possible rational roots must be of the form \(\huge \frac{\text{things in the first list}}{\text{things in the second list}}\)

  15. Mertsj
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    It is not factorable.

  16. Mertsj
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So the best approach would be to find where y changes sign. Then you would know there is a root between those two values and you could hone in on it by trial and error. Of if you know calculus, you could use the derivative. What class is this for?

  17. burhan101
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @Mertsj calculus !

  18. oldrin.bataku
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    they want you to bruteforce using newton's more than likely

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

    • Attachments:

Ask your own question

Ask a Question
Find more explanations on OpenStudy

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.