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

OCR (not MEI) C2 - Wednesday 20th May 2015 Watch

    Offline

    3
    ReputationRep:
    (Original post by chloe-jessica)
    y = -3 + 2root(x+4)
    (y + 3)/2 = root (x+4)
    x+4 = (y+3)(y+3)/4
    x+4 = (y^2 + 6y + 9) / 4
    x = 1/4(y^2 + 6y + 9) - 4
    x = 1/4(y^2 + 6y - 7)

    Then integrate as dx/dy with the limits of y=3 and y=1 and you should get the answer they want. Hope you can follow that okay
    Hi. When I did this question, I calculated the area from the curve to the x axis and then subtracted this from the area of the rectangle to find the area of that little area B. Do you think this is acceptable considering the context of the question?
    • Thread Starter
    Offline

    2
    (Original post by gabby07)
    Hi. When I did this question, I calculated the area from the curve to the x axis and then subtracted this from the area of the rectangle to find the area of that little area B. Do you think this is acceptable considering the context of the question?
    When we did this as a mock, a couple of my class did it this way and my teacher seemed to think that you'd lose marks for not writing the function in the form x=f(y) like it asks for. The mark scheme was posted on the previous page so you could try to work out what you'd be given from that
    Offline

    3
    ReputationRep:
    (Original post by chloe-jessica)
    When we did this as a mock, a couple of my class did it this way and my teacher seemed to think that you'd lose marks for not writing the function in the form x=f(y) like it asks for. The mark scheme was posted on the previous page so you could try to work out what you'd be given from that
    Yeah I thought so. The only reason I think I get confused in differentiation between to lines/ a line and a curve is when to take away the bottom one from the top one and when to just leave it (as you do in this question).
    • Thread Starter
    Offline

    2
    (Original post by gabby07)
    Yeah I thought so. The only reason I think I get confused in differentiation between to lines/ a line and a curve is when to take away the bottom one from the top one and when to just leave it (as you do in this question).
    Because this question was asking for an area between a curve and the y-axis, it was easiest to integrate y=... I'd just be careful and if it says to change the function into that form, do it. It's basically because at C3 you learn more about integration and the function they gave you in this question needs to be integrated in a different way (well technically this one was alright because of the numbers they'd chosen, but in the future this may not be true). For example, you can't integrate (7x+4)^4 without either expanding or using a rule you learn next year
    Offline

    3
    ReputationRep:
    Can't wait for June 3rd, after S1.

    No more maths after that as I'm dropping it in September.
    Offline

    1
    ReputationRep:
    Haha. Same here. How you feeling about s1? To me that's the hardest and most confusing


    Posted from TSR Mobile
    Offline

    3
    ReputationRep:
    (Original post by Matthewdang)
    Haha. Same here. How you feeling about s1? To me that's the hardest and most confusing


    Posted from TSR Mobile
    S1 is fine for me, except from permutations and combinations, as well as binomial and geometric distribution.

    In my opinion the order goes (easiest to hardest):
    C1<S1<C2
    Offline

    2
    ReputationRep:
    (Original post by Peppercrunch)
    S1 is fine for me, except from permutations and combinations, as well as binomial and geometric distribution.

    In my opinion the order goes (easiest to hardest):
    C1<S1<C2
    C2 easiest, then C1 then stats for me
    Offline

    2
    ReputationRep:
    (Original post by chloe-jessica)
    y = -3 + 2root(x+4)
    (y + 3)/2 = root (x+4)
    x+4 = (y+3)(y+3)/4
    x+4 = (y^2 + 6y + 9) / 4
    x = 1/4(y^2 + 6y + 9) - 4
    x = 1/4(y^2 + 6y - 7)

    Then integrate as dx/dy with the limits of y=3 and y=1 and you should get the answer they want. Hope you can follow that okay
    Thanks.

    Hopefully this years C2 paper will be nicer than last years.
    • Thread Starter
    Offline

    2
    (Original post by scrlk)
    Thanks.

    Hopefully this years C2 paper will be nicer than last years.
    Yeah last years was one of the harder ones which I've seen. Hopefully that means they'll make up for it with an easy one this year!
    Offline

    0
    ReputationRep:
    Anyone else got D2 straight after? Not looking forward to that morning at all😫


    Posted from TSR Mobile
    Offline

    2
    ReputationRep:
    (Original post by Abbie2511)
    Anyone else got D2 straight after? Not looking forward to that morning at all😫


    Posted from TSR Mobile
    I have D2 straight after, I'm fearing for my further maths grade with that paper. I absolutely hate it
    Offline

    0
    ReputationRep:
    (Original post by hallo.C)
    I have D2 straight after, I'm fearing for my further maths grade with that paper. I absolutely hate it
    I messed up FP1, which I supposedly find the easiest, so I need to get every mark I can in D1 and D2 which is so annoying


    Posted from TSR Mobile
    Offline

    0
    ReputationRep:
    (Original post by Peppercrunch)
    S1 is fine for me, except from permutations and combinations, as well as binomial and geometric distribution.

    In my opinion the order goes (easiest to hardest):
    C1<S1<C2
    who can even permutation or combination
    Offline

    3
    ReputationRep:
    Hi can I just check with someone, if you are using the formula for Sn for a Geometric Progression:

    \frac{a(1 - r^n)}{1-r}

    with a value of r which is greater than 1, do you switch the equation to:

    \frac{a(r^n - 1)}{r-1}

    Is this correct??!
    Thanks
    Offline

    2
    ReputationRep:
    (Original post by Abbie2511)
    I messed up FP1, which I supposedly find the easiest, so I need to get every mark I can in D1 and D2 which is so annoying


    Posted from TSR Mobile
    We don't do D1 until core maths in Year 13 so I'm doing D2 without having been taught D1
    Offline

    2
    ReputationRep:
    Everybody ready for a horrible paper. Ocr has been following its reputation of last year. First a nice Core 1 paper, than a TERRIBLE physics paper and now we can expect a bad core 2 paper
    Offline

    2
    ReputationRep:
    https://68baf9f6baae001b7abe18b6e880...20C2%20OCR.pdf
    Q3(b) Help !
    Offline

    2
    ReputationRep:
    y²=27
    log3y² = log327
    2log3y = 3
    log3y = 1.5
    Offline

    2
    ReputationRep:
    (Original post by Sahil_)
    y²=27
    log3y² = log327
    2log3y = 3
    log3y = 1.5
    Where did you get the 272 or the log after it ?
 
 
 
Poll
How are you feeling about your A-level results?

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.