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    Hi guys, I haven't been taught any of C1,C2 so as result here we are... I understand most the content however this question I don't understand. I got the answer by integrating and it gave me 24. However when i check the mark scheme it has 36 as the answer apparently something with a rectangle... Any Help?

    I got part A right though... so that's something
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    When you integrate the curve between the 2 x values you found, you are finding the area under the curve, that is the area bound by the curve, the x axis and the 2 x values you found. This is not the shaded area.
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    (Original post by nwmyname)
    I will post some help shortly with a solution to your question.
    There is no need to post a solution - it is also against the forum's guidelines. It doesn't help as much as guiding the OP with hints. (plus, they also have a mark scheme so a solution will not be much use).
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    (Original post by SeanFM)
    There is no need to post a solution - it is also against the forum's guidelines. It doesn't help as much as guiding the OP with hints. (plus, they also have a mark scheme so a solution will not be much use).
    Oh fair enough. I'm still new to this site, apologies.

    Find the area under the line y = 10 first. Use the knowledge of the other line to estimate the line under the curve.

    Hint - you can define two integrals that have the same limit.
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    (Original post by nwmyname)
    Oh fair enough. I'm still new to this site, apologies.

    Find the area under the line y = 10 first. Use the knowledge of the other line to estimate the line under the curve.

    Hint - you can define two integrals that have the same limit.
    Thank you. it's okay, I made the same mistake myself.
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    Nice n easy...

    to find co-ordinates do 10=x^2+2x=2 as the lines intercept at y=10....so x^2+2x-8=0 factorise you get (x-2)(x+4) so x=2 or -4

    to integrate your finding the area under the curve between x=-4 and x=2 which is the unshaded bit

    so integrating (x^2+2X=2) you get I= (1/3X^3+X^2+2X) so then do top-bottom ( 1/3(2)^3+(2)^2+2(2) ) - ( 1/3(-4)^3+(-4)^2+2(-4)) so you get 24

    so now the area under the curve is 24(the unshaded bit between x=-4 and X=2 so to find the shaded bit find the area of the square between X=-4 to X=2 to Y=10 so (4+2)*10=60 then minus the 24 which gets your 36.
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    why you doing c2 now? exam are done
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    (Original post by TSRPAV)
    why you doing c2 now? exam are done
    Some people tend to start now upon their retake.
    Strange, but true.
    I don't know if this is the case for here.
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    (Original post by nwmyname)
    Some people tend to start now upon their retake.
    Strange, but true.
    I don't know if this is the case for here.
    oh ok, you doing c3 tomorrow?
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    (Original post by TSRPAV)
    oh ok, you doing c3 tomorrow?
    aha no i'm starting the c3 module.
    Are you doing C3 tomorrow?
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    (Original post by nwmyname)
    aha no i'm starting the c3 module.
    Are you doing C3 tomorrow?
    yeah i do and c4 on friday ah alright ahah good luck and keep ahead, it will get messy make sure to master differentiation cos integration is 100x harder at first but once you master that c3 and differentiation is easier than c1. If i were you id do some small pre reading over summer and then work ahead of the class when you get back. i got a C last year at As and now im targeted A* which is actually achievble now cos of it , key topics to master are c3 Trig and identities and differentiation and C4 integration. Good luck
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    (Original post by TSRPAV)
    yeah i do and c4 on friday ah alright ahah good luck and keep ahead, it will get messy make sure to master differentiation cos integration is 100x harder at first but once you master that c3 and differentiation is easier than c1. If i were you id do some small pre reading over summer and then work ahead of the class when you get back. i got a C last year at As and now im targeted A* which is actually achievble now cos of it , key topics to master are c3 Trig and identities and differentiation and C4 integration. Good luck
    Wish you luck.

    I made a post for people to post suggestions as to how to succeed A2 maths and posted your comment as a starter.
    Could you contribute any other suggestions?
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    (Original post by TSRPAV)
    why you doing c2 now? exam are done
    Ahahaha, no mocks since we're not taking the AS levels just doing it all next year.
 
 
 
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