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    Kate and john can smd if they appear tomorrow

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    (Original post by Story)
    I got up to integrate 1/4+u * 2u . du am I along the right lines?
    Is that:

    \dfrac{2u}{4+u}

    If so, did you take the substitution u^2 = x-1 ?

    I suggest taking the substitution of u = 4+(x-1)^{\frac{1}{2}}, it's far easier that way.

    (Original post by otrivine)
    Can I integrate using the sub method?

    or can I use integral sign , a^x/Ina +C ?
    Sorry, what question's this?
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    (Original post by wndms)
    I started today. I think its better than nothing

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    Started them on Saturday and managed to finish them all by today There good help for the harder questions (There vector questions are harder)
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    (Original post by usycool1)
    Is that:

    \dfrac{2u}{4+u}

    If so, did you take the substitution u^2 = x-1 ?

    I suggest taking the substitution of u = 4+(x-1)^{\frac{1}{2}}, it's far easier that way.



    Sorry, what question's this?

    Do you not get the same thing if you differentiate that as u ?
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    Can someone please send me the leaked paper for june 2012 c4?
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    Anyone know how to integrate x/(x+1)?


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    Can anyone please help me with this c4?
    Fir part c) I know you have to equate dy/dx to 0. But then what do you do after? The answer is supposed to be (pi,-1). I don't understand .. thanks!

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    (Original post by wndms)
    Can anyone please help me with this c4?
    Fir part c) I know you have to equate dy/dx to 0. But then what do you do after? The answer is supposed to be (pi,-1). I don't understand .. thanks!

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    sub into y.
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    (Original post by DonkBets)
    i used the limits 2 and 0.5 too, but my answer was wrong.
    I kinda hope it comes up tomorrow now ^^ (i missed out a step in part c, if you want it explaining just ask)
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    Does anyone have the june 12 leaked paper and mark scheme for c4?
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    (Original post by wndms)
    Can anyone please help me with this c4?
    Fir part c) I know you have to equate dy/dx to 0. But then what do you do after? The answer is supposed to be (pi,-1). I don't understand .. thanks!

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    \dfrac{dy}{dx} = 0 \ \Rightarrow \ - \cot \frac{\theta}{2} = 0

    \Rightarrow \ - \dfrac{\cos \frac{\theta}{2}}{\sin \frac{\theta}{2}} = 0 \ \Rightarrow \ \cos \frac{\theta}{2} = 0
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    (Original post by usycool1)
    Is that:

    \dfrac{2u}{4+u}

    If so, did you take the substitution u^2 = x-1 ?

    I suggest taking the substitution of u = 4+(x-1)^{\frac{1}{2}}, it's far easier that way.



    Sorry, what question's this?
    The question you answered, and I asked is this integration ?
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    (Original post by linamoore)
    Does anyone have the june 12 leaked paper and mark scheme for c4?
    Mark Scheme: http://www.thestudentroom.co.uk/atta...7&d=1369299296
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    (Original post by wndms)
    Can anyone please help me with this c4?
    Fir part c) I know you have to equate dy/dx to 0. But then what do you do after? The answer is supposed to be (pi,-1). I don't understand .. thanks!

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    How do you even do question part a or b?
    :/.
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    (Original post by AHarris)
    Anyone know how to integrate x/(x+1)?


    Posted from TSR Mobile
    \dfrac{x}{x+1}

    = \dfrac{x+1-1}{x+1}

    = \dfrac{x+1}{x+1} - \dfrac{1}{x+1}

    = 1 - \dfrac{1}{x+1}


    \therefore \displaystyle \int \dfrac{x}{x+1} \ dx = \int \left( 1 - \dfrac{1}{x+1} \right) dx  = x - \ln (x+1) + C
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    (Original post by PoorLoser)
    can you give an example of a question of this type?
    I can't think of an example in a paper or in the textbook (I know there was at least one, but I can't remember which one it would be!), but an example would be if you were taking the integral of 1/x between -3 and -2
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    (Original post by justinawe)
    \dfrac{x}{x+1}

    = \dfrac{x+1-1}{x+1}

    = \dfrac{x+1}{x+1} - \dfrac{1}{x+1}

    = 1 - \dfrac{1}{x+1}


    \therefore \displaystyle \int \dfrac{x}{x+1} \ dx = \int \left( 1 - \dfrac{1}{x+1} \right) dx  = x - \ln (x+1) + C
    Would you consider that to be a harder integrand? It doesnt seem clear that thats how ts is done.

    Thanks
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    Anyone have the paper for this?
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    I have no idea how to answer any vector questions but I should be okay at getting 70 UMS+ as long as they only ask 1 vector question. Have any past papers asked more than 1 vector question?
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    can anyone write me the solution in a sheet for the question 7c) (28 january 2012 paper)...im so confused..!!thanks in advance!!
 
 
 
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