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    How on earth do i start this , can someone please explain me bit more about substitution integration.
    I seem to have got basic idea of it but i dont get the right answers =/

    =/ well i started off by first differentiating u= 4x+1
    => du/dx = 4 , du= 4dx , dx= 1/4du
    now this is where i screw up , i think =/
    before Integration:
    2x / (4x+1)^2
    => after: x^2 (-u)^-1 x1/4 du (where i believe du becomes constant ?)
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    (Original post by ibysaiyan)
    How on earth do i start this , can someone please explain me bit more about substitution integration.
    I seem to have got basic idea of it but i dont get the right answers =/

    =/ well i started off by first differentiating u= 4x+1
    => du/dx = 4 , du= 4dx , dx= 1/4du
    now this is where i screw up , i think =/
    before Integration:
    2x / (4x+1)^2
    => after: x^2 (-u)^-1 x1/4 du (where i believe du becomes constant ?)
    your use of notation makes it very difficult to follow what you are doing.
    Anyway, just replace all instances of x in the original equation with the proposed substitution , simplify and integrate.

    there should not be any "x's" once you have made your substitutions ....
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    Sorry about my lack of latex skill =/ , but i still dont get it. what you mean is that i need to replace all the "x's" into (4x+1)?
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    OHHH! I think i get it now thanks alot , i wasn't subbing in x values ^^ oh nvm
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    (Original post by ibysaiyan)
    Sorry about my lack of latex skill =/ , but i still dont get it. what you mean is that i need to replace all the "x's" into (4x+1)?
    eh?

    I'm sorry, but I really am struggling to understand what you mean.

    you suggested using the substitution u=4x+1

    well x=(u-1)/4 ........ so use it !!
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    (Original post by Mrm.)
    eh?

    I'm sorry, but I really am struggling to understand what you mean.

    you suggested using the substitution u=4x+1

    well x=(u-1)/4 ........ so use it !!
    Roger that. lol seems i cant multi-task .
 
 
 
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Updated: January 16, 2010
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