Join TSR now and get all your revision questions answeredSign up now
    Offline

    1
    ReputationRep:
    (Original post by thewagwag)
    you don't have to, but it makes it all much clearer. usually it's quite obvious, so if there is an [f(x)]^2, you'll want to use u = f(x). anything particularly obscure they tend to give you don't they?
    okay then thanks !
    Offline

    0
    ReputationRep:
    (Original post by Myda)
    I used a really basic example to just show you the chain rule, and yes it is by differentiating further because if you have y= a function with a power, then you also need to consider the derivative of the function. So we had y= (tanx)^3
    Let y = t^3 where t= tan x
    Dy/dt is 3t^2 and dt/dx = sec^2x
    Now put these together and you get dy/dx = 3t^2 x sec^2x but you know t= tanx so replace and you get 3(tanx)^2sec^2x

    Remember you're trying to intergrate and this method of working with differentiation is known as using reverse of chain rule, where you sort of work backwards from using differentiation to get your integral. Look in the book as well I'm sure their examples will help too
    OH i get it!!
    thanks!
    Offline

    0
    ReputationRep:
    (Original post by PoorLoser)
    OH i get it!!
    thanks!
    Haha no problem!
    Offline

    0
    ReputationRep:
    Are there any special forms or integration tips that you can provide for C4?
    Or any forms of fractions or something that I don't know

    For example I got a question in the form a^x and I just didn't know what to do with it ....
    Also stuff like sin^3x and things like that how will I be able to spot/make it easier in a form which I can integrate?

    Thanks - any help/tips would be useful!
    Offline

    2
    ReputationRep:
    Name:  ImageUploadedByStudent Room1370932228.533355.jpg
Views: 118
Size:  178.9 KBCan anyone tell me what is this alternative method ? Its from edexcel c3 jan07 q6e
    Thanks!



    Posted from TSR Mobile
    • Thread Starter
    Offline

    1
    ReputationRep:
    Please can someone send me January 2013 Markschemes i need to mark my paper ASAP!!!!
    Offline

    1
    ReputationRep:
    (Original post by Better)
    Please can someone send me January 2013 Markschemes i need to mark my paper ASAP!!!!
    just look at Arsey's solutions on the Jan 2013 thread on TSR
    Offline

    0
    ReputationRep:
    (Original post by PoorLoser)
    is the answer 6/x ?
    2/3x
    • Thread Starter
    Offline

    1
    ReputationRep:
    (Original post by pepeeglesfield)
    just look at Arsey's solutions on the Jan 2013 thread on TSR
    Found a Website. Will upload the Paper and Markscheme later if anyone wants it.
    Offline

    0
    ReputationRep:
    (Original post by Lamalam)
    Name:  ImageUploadedByStudent Room1370932228.533355.jpg
Views: 118
Size:  178.9 KBCan anyone tell me what is this alternative method ? Its from edexcel c3 jan07 q6e
    Thanks!



    Posted from TSR Mobile
    That's the way I got taught- If you substitute two values of k to 1 more decimal place above and below into g(x) you should get a positive and a negative value. Therefore g(x) is equal to zero in that interval because the sign has changed. By choosing values of k that round to -0.352 you prove that k is equal to -0.352 to 3 decimal places. Hope this helps.
    • Thread Starter
    Offline

    1
    ReputationRep:
    Might do 2 C4 papers tomorrow just so that I'm on at least the 2009 papers by the end of Thursday

    Looking forward to C3.
    Offline

    0
    ReputationRep:
    I have just finished my revision for C3, coul

    can someone post the hardest questions for each chapter, I want to see how I get on with it.
    Offline

    1
    ReputationRep:
    (Original post by Baraf)
    I have just finished my revision for C3, coul

    can someone post the hardest questions for each chapter, I want to see how I get on with it.
    I second this...have you done any solomon papers?
    Offline

    1
    ReputationRep:
    Graphically, what are we supposed to be able to sketch for C3? I know there are all these transformations, not including them. Just general graphs we should know. I'm not a big fan of graphs so I thought I best sort myself out Also are the solomons good for C3? Did people find them helpful?
    Offline

    1
    ReputationRep:
    Also I detest domain and range always struggle with them, don't like them for some reason. Any tips?
    Offline

    1
    ReputationRep:
    The formulaes we need to learn for C3 regarding trig are addition, double angle formulae, half angle formulae and factor formulae?

    Addition is given so is factor formulae.

    I've learnt double angle formulae, have people just memorised half-angle formulae too?
    Offline

    3
    ReputationRep:
    (Original post by sarah.102)
    The formulaes we need to learn for C3 regarding trig are addition, double angle formulae, half angle formulae and factor formulae?

    Addition is given so is factor formulae.

    I've learnt double angle formulae, have people just memorised half-angle formulae too?
    You can easily derive the double angle formulae from the addition formulae given.

    sin(2x) = sin(x+x) etc

    Half angle formulae are just the double angle formulae I'm pretty sure? Just replace all the 2x with x and all the x with x/2
    Offline

    1
    ReputationRep:
    (Original post by Taylor Swift)
    Are there any special forms or integration tips that you can provide for C4?
    Or any forms of fractions or something that I don't know

    For example I got a question in the form a^x and I just didn't know what to do with it ....
    Also stuff like sin^3x and things like that how will I be able to spot/make it easier in a form which I can integrate?

    Thanks - any help/tips would be useful!
    y = a^x
    lny = ln(a^x) = x*lna
    y = e^(x*lna)
    integral of y = 1/lna * e^(xlna) = (a^x)/ln(a)
    Offline

    0
    ReputationRep:
    guys please answer this question
    should i di all the excercises for chapter 7 in c3 the trigonometry chapter?
    or is it enough to do the exampels and mixed
    Offline

    1
    ReputationRep:
    (Original post by sarah.102)
    Graphically, what are we supposed to be able to sketch for C3? I know there are all these transformations, not including them. Just general graphs we should know. I'm not a big fan of graphs so I thought I best sort myself out Also are the solomons good for C3? Did people find them helpful?
    you need to be able to sketch graphs both linear and quadratic, both fairly simple, need to be able to apply graph transformations to these, whether they are mod functions, inverse functions, or stretches, you also need to be familiar with the trig graphs, their inverse, and the graphs of cot, cosec and sec

    edit: and yes solomon are fairly useful, especially when you run out of c3 papers, they test your knowledge in different ways than the usual past paper
 
 
 
Poll
Which pet is the best?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Quick reply
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.