Turn on thread page Beta
    • Thread Starter
    Offline

    0
    ReputationRep:
    Help needed, i'll appreciate if someone can show me how to do this question NOV 2004 P2 Paper:

    f:x --> Modulus 2x-5, X is set of Real Numbers

    (b) Find the values of x for which f(x)=x (4 Marks)

    The function g is defined by g: --> x(x-6), X is set of Real Numbers

    (c) Find the range of g(x)

    Many Thanx and Rep will be given!!!
    Offline

    0
    ReputationRep:
    (Original post by Steve8052)
    Help needed, i'll appreciate if someone can show me how to do this question NOV 2004 P2 Paper:

    f:x --> Modulus 2x-5, X is set of Real Numbers

    (b) Find the values of x for which f(x)=x (4 Marks)

    The function g is defined by g: --> x(x-6), X is set of Real Numbers

    (c) Find the range of g(x)

    Many Thanx and Rep will be given!!!
    (b) f(x) = |2x - 5| = x
    => -x = 2x - 5 => x = 5/3
    => -x = -2x + 5 => x = 5

    (c) g(x) = x^2 - 6x
    g'(x) = 2x - 6 => x = 3 at minimum
    g(3) = 9 - 18 = -9
    Therefore g(x) > -9
    Offline

    2
    ReputationRep:
    b) Then x= |2x-5|
    So x²=(2x-5)²=4x²-20x+25
    So 3x²-20x+25=0
    Solve quadratic:

    x=(20±√(400-300))/6 = (20±10)/6
    x either = 30/6=5 or 10/6=5/3

    c) Expand the function to give x²-6x
    Differentiatiate to give minima and maxima: 2x-6=0 x=3 is your minimum.

    y=3*3 - 6*3 = 9-18=-9
    g(x) is more than or equal to -9
    • Thread Starter
    Offline

    0
    ReputationRep:
    Thanx Guys Help Appreciated!! Didnt know had to Differentiate that.
 
 
 
Turn on thread page Beta
Updated: June 19, 2005
The home of Results and Clearing

3,016

people online now

1,567,000

students helped last year

University open days

  1. SAE Institute
    Animation, Audio, Film, Games, Music, Business, Web Further education
    Thu, 16 Aug '18
  2. Bournemouth University
    Clearing Open Day Undergraduate
    Fri, 17 Aug '18
  3. University of Bolton
    Undergraduate Open Day Undergraduate
    Fri, 17 Aug '18
Poll
Do you want your parents to be with you when you collect your A-level results?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

How to use LaTex

Writing equations the easy way

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.