Results 1 to 3 of 3

Math Help - halving the interval

  1. #1
    Member
    Joined
    Aug 2009
    Posts
    96

    halving the interval

    f(x) = x^3 + 5x^2 + 17x - 10.
    The equation f(x) = 0 has only one real root.

    i. Show the root lies between 0 and 2

    ii. use one application of 'halving the interval' to find a smaller interval

    iii. Which end of the smaller interval found in ii. is closer to the root? Why?

    for i. i got
    P(0) = -10 -neg
    P(2) = 52 -pos
    therefore the root lies between 0 and 2

    ii. P(1) = 13 -pos
    therefore the root lies between 0 and 1

    are these right??
    how do you do iii.?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    ynj
    ynj is offline
    Senior Member
    Joined
    Jul 2009
    Posts
    254
    Quote Originally Posted by deej813 View Post
    f(x) = x^3 + 5x^2 + 17x - 10.
    The equation f(x) = 0 has only one real root.

    i. Show the root lies between 0 and 2

    ii. use one application of 'halving the interval' to find a smaller interval

    iii. Which end of the smaller interval found in ii. is closer to the root? Why?

    for i. i got
    P(0) = -10 -neg
    P(2) = 52 -pos
    therefore the root lies between 0 and 2

    ii. P(1) = 13 -pos
    therefore the root lies between 0 and 1

    are these right??
    how do you do iii.?
    P(0.5)<0,so the root is greater than 0.5, then 1 is nearer..
    i,ii are right.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Aug 2009
    Posts
    96
    ok thanks
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. interval for f'(x)>0
    Posted in the Calculus Forum
    Replies: 6
    Last Post: February 10th 2010, 04:54 AM
  2. halving a rectangle
    Posted in the Pre-Calculus Forum
    Replies: 5
    Last Post: January 11th 2010, 03:50 AM
  3. [SOLVED] Halving the interval (bisection)?
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: January 31st 2009, 10:06 AM
  4. Interval
    Posted in the Algebra Forum
    Replies: 1
    Last Post: May 18th 2008, 03:39 PM
  5. Increasing interval and decreasing interval
    Posted in the Calculus Forum
    Replies: 4
    Last Post: February 24th 2006, 08:49 AM

Search Tags


/mathhelpforum @mathhelpforum