Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

Maths Q

  • 02-06-2013 12:09pm
    #1
    lizardspock
    Registered Users, Registered Users 2 Posts: 46 ✭


    Hi,
    could anyone explain to me what the term injective means? and how do you test a function to see if it is injective?? Question came up about it the 2012 HL sample paper
    thanks :)


Comments

  • #2
    Parawhore.xD
    Registered Users, Registered Users 2 Posts: 571 ✭✭✭Parawhore.xD


    lizardspock wrote: »
    Hi,
    could anyone explain to me what the term injective means? and how do you test a function to see if it is injective?? Question came up about it the 2012 HL sample paper
    thanks :)

    I had the same question last week and was freaking out because I couldn't find the answer anywhere, turns out it's not on our course but on the next phase for this year's 5th years, that paper is a pilot school paper according to my teacher so some of the calculus/functions and graphs stuff aren't our syllabus.

    Reaaaaally frustrating when you're this close to the Leaving and you're seeig all these things you can't do!


  • #3
    Acciaccatura
    Registered Users, Registered Users 2 Posts: 428 ✭✭Acciaccatura


    I'm in a pilot school and I don't know what injective means :eek: I'll be back when I find the answer!

    EDIT: Found out on Wiki, it's basically that if a function is injective, no two values of X will produce the same value of Y, i.e. " it never maps distinct elements of its domain to the same element of its codomain. In other words, every element of the function's codomain is the image of at most one element of its domain. If in addition all of the elements in the codomain are in fact the image of some element of the domain, then the function is said to be bijective". Panic over.
    There's a bit of info that's utterly useless to ye now :P


  • #4
    lizardspock
    Registered Users, Registered Users 2 Posts: 46 ✭lizardspock


    Parawhore.xD wrote: »
    I had the same question last week and was freaking out because I couldn't find the answer anywhere, turns out it's not on our course but on the next phase for this year's 5th years, that paper is a pilot school paper according to my teacher so some of the calculus/functions and graphs stuff aren't our syllabus.

    Reaaaaally frustrating when you're this close to the Leaving and you're seeig all these things you can't do!


    So glad to hear that- Was really annoying me why I had never hear of the term before, so thank you! Oh how I love project maths and its messy syllabus... :rolleyes:


  • #5
    Parawhore.xD
    Registered Users, Registered Users 2 Posts: 571 ✭✭✭Parawhore.xD


    lizardspock wrote: »
    So glad to hear that- Was really annoying me why I had never hear of the term before, so thank you! Oh how I love project maths and its messy syllabus... :rolleyes:

    Each I know what you mean. It just seems to add so much unnecessary stress...


Advertisement