Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

burhan101

  • 3 years ago

When [equation] is divided by (x-1) the remainder is 7. When it is divided by (x+1) the remainder is 3. Determine the values of a &b . Can somebody please just explain the method... thanks:)

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

    \[\huge x^4-4x^3+ax^2+bx+1 \]

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

    Have you tried synthetic division?

  3. burhan101
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    but there are 3 variables .. :S

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

    Yeah but you know a lot of algebra to deal with them.

  5. wio
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Hmmm, I'm not exactly sure what the trick for this is.

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

    \[ \large x^4-4x^3+ax^2+bx+1=(x-1)(cx^3+dx^2+ex+f)+7 \]

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

    @ burhan101 use factor and remainder theorem

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

    when f(x) is divided by (x-a) the remainder is given by f(a)

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

    thus here f(x) =x^4−4x^3+ax^2+bx+1 f(1)=7 and f(-1)=3 u will get two equation in two unknowns and u can solev them to know a and b

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

    thus a+b=9 and a-b -3 thus solving above two eq we have a=3 and b=6

  11. 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