Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    7
    ReputationRep:
    The question is asking me to circle the equation with roots 4 and -8 and the options are: 4x(x-8)=0, (x-4)(x+8)=0, x^2 -32 = 0 and (x+4)(x-8)=0. The answer is not what I'm interested in but more so how to go about answering similar questions like these
    Offline

    2
    ReputationRep:
    A polynomial with roots  \alpha, \beta, \gamma .... \zeta has equation  (x-\alpha)(x-\beta)(x-\gamma)...(x-\zeta) .
    Since when you plug in one of the roots for x it will be equal to 0.
    Offline

    11
    ReputationRep:
    Ok so first of all solve each of the x values when the equation is equal to 0

    For example on the first one, 4x=0 and x-8=0

    what are the roots of this first equations? (ie what are the values of x)

    repeat this method for the other three equations
    Offline

    3
    ReputationRep:
    (Original post by Botcampers)
    The question is asking me to circle the equation with roots 4 and -8 and the options are: 4x(x-8)=0, (x-4)(x+8)=0, x^2 -32 = 0 and (x+4)(x-8)=0. The answer is not what I'm interested in but more so how to go about answering similar questions like these
    isn't this a question in the new gcse maths paper(aqa)
    • Thread Starter
    Offline

    7
    ReputationRep:
    (Original post by theBranicAc)
    isn't this a question in the new gcse maths paper(aqa)
    Not sure. My teacher gave it to me so I could revise
    • Thread Starter
    Offline

    7
    ReputationRep:
    (Original post by Katiee224)
    Ok so first of all solve each of the x values when the equation is equal to 0

    For example on the first one, 4x=0 and x-8=0

    what are the roots of this first equations? (ie what are the values of x)

    repeat this method for the other three equations
    Oh! That makes sense. I was baffled by the word root but now it makes sense. Just look for the values of X. Thank you
    Offline

    11
    ReputationRep:
    (Original post by Botcampers)
    Oh! That makes sense. I was baffled by the word root but now it makes sense. Just look for the values of X. Thank you
    The values of x are when y=0. If you plotted the graph of each of these equations you would see this is where the graph crosses the x-axis.

    I recommend you draw out the graphs to see visually where the routes are once you've found them.
    Offline

    2
    ReputationRep:
    Just to elaborate, this is why we set equations to 0 and factorise, if a polynomial has roots, 2, 3 , 1 and -1 then its equation would be  y=(x-2)(x-3)(x-1)(x+1) .
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Brexit voters: Do you stand by your vote?
    Useful resources

    Study tools

    Rosette

    Essay expert

    Learn to write like a pro with our ultimate essay guide.

    Thinking about uni already?

    Thinking about uni already?

    See where you can apply with our uni match tool

    Student chat

    Ask a question

    Chat to other GCSE students and get your study questions answered.

    Creating

    Make study resources

    Create all the resources you need to get the grades.

    Planner

    Create your own Study Plan

    Organise all your homework and exams so you never miss another deadline.

    Resources by subject

    From flashcards to mind maps; there's everything you need for all of your GCSE subjects.

    Papers

    Find past papers

    100s of GCSE past papers for all your subjects at your fingertips.

    Help out other students

    Can you help? Study help unanswered threads

    Groups associated with this forum:

    View associated groups
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • 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.