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    (taken from the June 2009 AQA FP3 paper)

    Hi, could someone please explain to me the step for the third M1 mark? - where you divide all the terms by 'a'.

    I understand that this is what you do, as my teach briefly mentioned it, but I don't know why???? Why do you have to do that step? Name:  Screen Shot 2018-03-04 at 14.59.30.png
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    (Original post by imundercover)
    (taken from the June 2009 AQA FP3 paper)

    Hi, could someone please explain to me the step for the third M1 mark? - where you divide all the terms by 'a'.

    I understand that this is what you do, as my teach briefly mentioned it, but I don't know why???? Why do you have to do that step? Name:  Screen Shot 2018-03-04 at 14.59.30.png
Views: 10
Size:  161.3 KB
    If u try to find the limit without having done the third m1 mark then its pretty hard.

    By dividing through a u get only 1 a term which u can clearly see the limit of.

    Essentially u are rewriting the term in brackets to find the limit easier.

    Hopefully someone else can clarify it further for u.
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    Basically a/(4a+1)=1/(4+1/a) provided a is not 0 (which thankfully for us doesn't change the limit) and so the limits of the two equivalent fractions (equivalent provided a is not 0) is the same. Now the limit of the second fraction is easy because we know 1/a goes to 0 as we let a tend to infinity. So the limit is just 1/(4+0)=1/4. Just divided by a makes the limit more clear and obvious that all.
 
 
 
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