Results 1 to 4 of 4

Math Help - Pre-Calc Help Please!

  1. #1
    Newbie
    Joined
    Jan 2006
    Posts
    20

    Pre-Calc Help Please!

    I had a problem that states: "Determine all values of k such that x^2-kx-6 can be factored by x-2." I had no idea what the answer was and left it blank. Can you please tell me how i would go through doing a problem like that. Thank you.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Global Moderator

    Joined
    Nov 2005
    From
    New York City
    Posts
    10,616
    Thanks
    10
    Quote Originally Posted by aussiekid90
    I had a problem that states: "Determine all values of k such that x^2-kx-6 can be factored by x-2." I had no idea what the answer was and left it blank. Can you please tell me how i would go through doing a problem like that. Thank you.
    Remember by the theory of polynomial (x-2) is a factor of f(x)=x^2-kx-6 only if 2 is a zero of this polynomial, thus, f(2)=0, thus, 4-2k-6=0 thus, k=-1.

    Now for the check, the polynomial is x^2+x-6 which factors into (x+3)(x-2) thus, it works.
    Q.E.D.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Jan 2006
    Posts
    20
    Would this be the only possiblity because the problem states find all possible solutions for K
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Global Moderator

    Joined
    Nov 2005
    From
    New York City
    Posts
    10,616
    Thanks
    10
    Quote Originally Posted by aussiekid90
    Would this be the only possiblity because the problem states find all possible solutions for K
    Yes, look at my derivation, only one possibility.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Calc 1 review for Calc 2
    Posted in the Calculus Forum
    Replies: 5
    Last Post: April 28th 2011, 04:47 AM
  2. A few Pre-Calc problems in my AP Calc summer packet
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: August 30th 2010, 04:40 PM
  3. Replies: 1
    Last Post: January 13th 2010, 12:57 PM
  4. What am I doing? Calc, Pre-calc, Trig, etc...
    Posted in the Math Topics Forum
    Replies: 1
    Last Post: April 23rd 2008, 09:51 AM
  5. Adv Calc lim prf
    Posted in the Calculus Forum
    Replies: 1
    Last Post: October 6th 2007, 10:25 AM

Search Tags


/mathhelpforum @mathhelpforum