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    i can find the answer using integration by substitution but cant seem to get the same answer when working it out using integration by parts

    ∫x(2x+1)³ and the limits are 1,0
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    Try u=x and v'=(2x+1)^3

    Substitution is easier, does the question ask for parts?
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    (Original post by Estelle123)
    i can find the answer using integration by substitution but cant seem to get the same answer when working it out using integration by parts

    ∫x(2x+1)³ and the limits are 1,0
    If you show us your working we could show you where you're going with using Integration by Parts.
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    I tried both, got different answers...i think i'm tired though.
    The shortest method on paper is to expand the brackets, think about it...no negatives to deal with, and the limit at 0 is 0.
    I got 71/10 for two of the answers
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    (Original post by jameswhughes)
    Try u=x and v'=(2x+1)^3

    Substitution is easier, does the question ask for parts?
    yh i no i got the right answer for substitution but unfortunately they ask for it in parts too
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    (Original post by deltabomber)
    I tried both, got different answers...i think i'm tired though.
    The shortest method on paper is to expand the brackets, think about it...no negatives to deal with, and the limit at 0 is 0.
    I got 71/10 for two of the answers
    ahh ok yes thats the right answer so I'll try it that way thanks!
 
 
 
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