Results 1 to 3 of 3

Math Help - Determine the Value of K.

  1. #1
    Member
    Joined
    Jun 2009
    Posts
    86

    Determine the Value of K.

    "If f(x) = x^2 - 6x + 14 and g(x) = -x^2 - 20x - k, determine the value of k so that there is exactly one point of intersection between the two parabolas."

    This is what I've done so far:

    f(x) + g(x) = 0
    -26x + 14 - k = 0
    a = 0, b = -26, c = (14 - k)
    b^2 - 4ac = 0
    (-26)^2 - 4(0)(14 - k) = 0
    676 - 0 = 0

    Based on the fact that this method cannot solve for k, I've come to believe that this attempt at a solution was wrong. Though I can't think of any other way of solving this. Help would be appreciated.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Banned
    Joined
    Oct 2009
    Posts
    4,261
    Quote Originally Posted by shadow6 View Post
    "If f(x) = x^2 - 6x + 14 and g(x) = -x^2 - 20x - k, determine the value of k so that there is exactly one point of intersection between the two parabolas."

    This is what I've done so far:

    f(x) + g(x) = 0


    Why plus?! The two parabolas meet when f(x)=g(x)\Longleftrightarrow f(x)-g(x)=0 ...!

    Tonio


    -26x + 14 - k = 0
    a = 0, b = -26, c = (14 - k)
    b^2 - 4ac = 0
    (-26)^2 - 4(0)(14 - k) = 0
    676 - 0 = 0

    Based on the fact that this method cannot solve for k, I've come to believe that this attempt at a solution was wrong. Though I can't think of any other way of solving this. Help would be appreciated.
    .
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Jun 2009
    Posts
    86
    Thanks for the correction. Got a final answer of 10.5.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. determine the value of a
    Posted in the Algebra Forum
    Replies: 1
    Last Post: August 24th 2010, 01:50 AM
  2. Replies: 1
    Last Post: May 18th 2010, 10:31 PM
  3. Replies: 1
    Last Post: April 22nd 2009, 03:05 AM
  4. Determine a Dif EQ
    Posted in the Calculus Forum
    Replies: 6
    Last Post: December 10th 2007, 01:24 PM
  5. Determine the value of a
    Posted in the Algebra Forum
    Replies: 4
    Last Post: June 29th 2006, 05:11 PM

Search Tags


/mathhelpforum @mathhelpforum