Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Polynomial Factors

  1. Oct 11, 2007 #1
    This problem came up on a math contest the other day and I drew a blank - now it's bugging me.

    "If the polynomial P(x)=x^2+ax+1 is a factor of T(x)=2x^3-16x+b, find the values of a and b."

    Anyone have any ideas?
  2. jcsd
  3. Oct 11, 2007 #2
    We have that there is a c such that (x^2+ax+1)(2x+c)=2x^3-16x+b. Thus comparing coefficients gives us:


    Solving this yields

    a=3 or -3, and thus
    b=-6 or 6
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook