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    guys my mind has gone blank
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    (Original post by gress12)
    ...
    Oh dear...

    What happens to the second bracket when x=k ??
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    Put k in mate and you get -8
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    (Original post by RDKGames)
    Oh dear...

    What happens to the second bracket when x=k ??
    k is -8?
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    (Original post by gress12)
    k is -8?
    k is not equal to -8...

    The answer is, the variable k isn't...
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    sub in k to get (3k-2)(k-k)-8.
    (3k-2)(k-k)=0
    therefore f(k)=-8
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    (Original post by RDKGames)
    k is not equal to -8...

    The answer is, the variable k isn't...
    i meant
    if you sub k into the second bracket
    you get k - k
    so is k = -8?
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    (Original post by gress12)
    i meant
    if you sub k into the second bracket
    you get k - k
    so is k = -8?
    Again, k\neq -8. It COULD be, but doesn't have to be. There is nothing to say that it must be, so why would it be??

    f(k)=-8 though...
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    (Original post by RDKGames)
    Oh dear...
    My thoughts too. OP you're doing A Level maths and you don't know how a function works (tbh even if you don't know what a function is this question is still trivial).
    Before tackling past paper Qs you really should be familiar with the very basics such as what functions are. Although if the exam is this year then it's probably too late.

    This is the reason why people do 'so well' in papers and then flop the real exam. It's because people get used to doing standard Qs by rote and then when the examiner even slightly changes one thing ('changes', not even necessarily 'make more difficult'), everyone struggles because they don't understand any of the maths or even have their fundamentals sorted out.
 
 
 
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