Results 1 to 3 of 3
Like Tree1Likes
  • 1 Post By InteGrand

Thread: Sydney Grammar 2009 help

  1. #1
    New Member
    Join Date
    Jul 2016
    HSC
    N/A
    Gender
    Undisclosed
    Posts
    11
    Rep Power
    2

    Sydney Grammar 2009 help

    Screen Shot 2017-09-17 at 8.34.25 am.png
    Screen Shot 2017-09-17 at 8.34.03 am.png
    I've attached the question I don't understand. specifically, I don't understand the 3rd line of the solution, which states there is a double root at the y-coordinates of the stationary points? is that a rule where y-f(x) = 0 has a double root at y=f'(x)??

  2. #2
    Ancient Orator
    Join Date
    Dec 2014
    HSC
    N/A
    Gender
    Male
    Posts
    5,971
    Rep Power
    6

    Re: Sydney Grammar 2009 help

    Quote Originally Posted by mathpie View Post
    Screen Shot 2017-09-17 at 8.34.25 am.png
    Screen Shot 2017-09-17 at 8.34.03 am.png
    I've attached the question I don't understand. specifically, I don't understand the 3rd line of the solution, which states there is a double root at the y-coordinates of the stationary points? is that a rule where y-f(x) = 0 has a double root at y=f'(x)??
    kawaiipotato likes this.

  3. #3
    New Member
    Join Date
    Sep 2017
    HSC
    N/A
    Gender
    Undisclosed
    Posts
    7
    Rep Power
    1

    Re: Sydney Grammar 2009 help

    Nice question
    Just use the formula in a) with p=3 to yield q=plus or minus 2
    This means that y=x^3-3x+2 and y=x^3-3x-2 both have double roots....ie max or min situated at the x axis
    Sliding y=x^3-3x+2 down 2 units gives a stationary point for y=x^3-3x with a y-value of -2. Similarly for the other

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •