A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 5 years ago

consider f(x) = 2x^2-3x-2 use factoring to solve for the zeros of f

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

    (2x+1)(x-2) x=-(1/2) and 2

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

    is that all?

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

    that should be all i think haha

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

    how did you do this problem just so i know how to do it?

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

    so, there are two ways 1) using the quadratic formula 2) (this one is probably what you Should be doing at this point seems like) is to use trial and error to see *what* multiplied by *what* gives you x^2-3x-4 if you multiply (2x+1)(x-2), you get x^2-3x-4

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

    so the ultimate goal of this problem is to find the zeros you have to make it into this equation x^2-3x-4=0 then (2x+1)(x-2)=0 then what "x" makes a zero? -(1/2) and 2

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

    oh ok i see

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

    i saw that part but what did you do to get (2x+1) and (x-2)

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

    sorry for the late reply.. you just have to try and see what works with practice, you can get it more quickly/see commonalities in problems

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

    i mean what did you do to get it? that is probably the same way i would do it.

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

    erm.. well, i guess when i see something like 2x^2-3x-2 i first put (2x )(x ) then i look at the last number and see that it's got to be -2*1 or 2*-1 then it's just matter of which works (2x+2)(x-1) or (2x-1)(x+2)

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

    so its what multiples to -2 and adds to -3?

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

    o oops, in hast, i put the wrong factors in my last post, but you understand i'm not sure what you're asking but i guess yes the middle term is the result of the addition of the 2nd terms in the factor (if there's no coefficient in the first term) so let's say (x+1)(x-2) the middle term would be 1x (as -2+1 is 1) actually.. i might be making this more confusing do you understand so far?

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

    im beginning to understand it

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

    so its not 2x+1

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

    ?

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

    you mean "so one of the factors isn't (2x+1)"? it is if you multiply through.. (2x+1)(x-2) = 2x*x + 2x*-2 + 1*x + 1*-2 =2x^2 - 4x + x - 2 = 2x^2 - 3x - 2

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

    if it's too confusing now...you might just be best advised to learn it in class where it may be better explained

  19. 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.