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AQA C3 June 2014 Unofficial Mark Scheme

Below is my unofficial mark scheme for today's C3 paper; mark schemes for other papers I have sat are linked at the bottom. I would appreciate it if anyone could contribute their answers, and if any of my answers are wrong give corrections. Marks are in emboldened, underlined brackets, like so [x]. Corrected answers that are still being debated are simply underlined, as so x.

The exam paper is attached to this post!

Unparseable latex formula:

[br]\begin{enumerate}[br]\item \int = 2.449 \hfill \textbf{\underline{[4]}} \\[br]\end{enumerate}[br]



Unparseable latex formula:

[br]\begin{enumerate}[br]\setcounter{enumi}{1}[br]\item[br]\begin{enumerate}[br]\item \dfrac{dy}{dx} = \dfrac{-2}{2e - x} \hfill \textbf{\underline{[2]}} \\[br]\item \text{Equation of Normal} = y-2=\dfrac{e}{2}(x-e) \hfill \textbf{\underline{[4]}} \\[br]\item [br]\begin{enumerate}[br]\item \text{Show} 1 \textless \alpha \textless 3 \hfill \textbf{\underline{[2]}} \\[br]\item x_2 = 2.980, x_3 = 1.798 \hfill \textbf{\underline{[2]}} \\[br]\item \text{Draw cobweb diagram} \hfill \textbf{\underline{[2]}} \\[br]\end{enumerate}[br]\end{enumerate}[br]\end{enumerate}[br]



Unparseable latex formula:

[br]\begin{enumerate}[br]\setcounter{enumi}{2}[br]\item[br]\begin{enumerate}[br]\item [br]\begin{enumerate}[br]\item \dfrac{d}{dx}[(x^{2}+1)^{\dfrac{5}{2}}] = 5x(x^{2}+1)^{\dfrac{3}{2}} \hfill \textbf{\underline{[2]}} \\[br]\item f'(0) = 2 \hfill \textbf{\underline{[3]}} \\[br]\end{enumerate}[br]\item \text{x-coordinates} = \dfrac{-1}{2}, 2 \hfill \textbf{\underline{[5]}} \\[br]\end{enumerate}[br]\end{enumerate}[br]



Unparseable latex formula:

[br]\begin{enumerate}[br]\setcounter{enumi}{3}[br]\item[br]\begin{enumerate}[br]\item \text{Sketch graph of} y=-\abs{f(x)} \hfill \textbf{\underline{[3]}} \\[br]\item \text{Sketch graph of} y=f(\abs{2x}) \hfill \textbf{\underline{[2]}} \\[br]\item[br]\begin{enumerate}[br]\item \text{Stretch, x-direction, sf} \dfrac{1}{2}, \text{Translate}[\dfrac{-1}{0}] \hfill \textbf{\underline{[4]}} \\[br]\item P'(1,-3) \hfill \textbf{\underline{[2]}} \\[br]\end{enumerate}[br]\end{enumerate}[br]\end{enumerate}[br]



Unparseable latex formula:

[br]\begin{enumerate}[br]\setcounter{enumi}{4}[br]\item[br]\begin{enumerate}[br]\item f(x) \geq -4 \hfill \textbf{\underline{[2]}} \\[br]\item f^{-1}(x) = 3+\sqrt{x+4} \hfill \textbf{\underline{[4]}} \\[br]\item[br]\begin{enumerate}[br]\item gf(x) = \abs{x^2 - 6x - 1} \hfill \textbf{\underline{[1]}} \\[br]\item x = 5, 7 \hfill \textbf{\underline{[4]}} \\[br]\end{enumerate}[br]\end{enumerate}[br]\end{enumerate}[br]



Unparseable latex formula:

[br]\begin{enumerate}[br]\setcounter{enumi}{5}[br]\item[br]\begin{enumerate}[br]\item \int = \dfrac{-x^{2}cos{2x}}{2} + \dfrac{xsin{2x}}{2} + \dfrac{cos{2x}}{4} + c \hfill \textbf{\underline{[6]}} \\[br]\item \text{Volume of revolution} = \pi(\dfrac{\pi^2}{8} - \dfrac{1}{2}) \hfill \textbf{\underline{[3]}} \\[br]\end{enumerate}[br]\end{enumerate}[br]



Unparseable latex formula:

[br]\begin{enumerate}[br]\setcounter{enumi}{6}[br]\item \dfrac{-1}{3} + ln{\dfrac{3}{2}} \hfill \textbf{\underline{[6]}} \\[br]\end{enumerate}[br]



Unparseable latex formula:

[br]\begin{enumerate}[br]\setcounter{enumi}{7}[br]\item[br]\begin{enumerate}[br]\item \text{Show expression can be written as} 2secx \hfill \textbf{\underline{[4]}} \\[br]\item x = 71, 180, 289 \hfill \textbf{\underline{[6]}} \\[br]\item \theta = 51, 105, 160 \hfill \textbf{\underline{[2]}} \\[br]\end{enumerate}[br]\end{enumerate}[br]



C1: http://www.thestudentroom.co.uk/showthread.php?t=2685494
C2: http://www.thestudentroom.co.uk/showthread.php?t=2689168
S1: http://www.thestudentroom.co.uk/showthread.php?t=2704980
(edited 9 years ago)

Scroll to see replies

Wasn't 2a -2/(2e-x)?
Reply 2
2a) is wrong its supposed to be -2/(2e-x)
8c the 51 degree angle should really be 50 degrees, but they will accept both.
5c is it not modulus of that?
Reply 5
and isint 4c) stretch by scale factor 1/2 paralleel to the x axis and translation of graph by -2 not -1
Is the answer to 2 a not -2/(2e-x), as the derivative of 2e - x is -1
Reply 7
btw guys does anyone remember the qs for 7a?? really wanna see where i went wrong :smile:
Reply 8
The paper if anyone wants it - include in the top post please
68/75

Really sad about 4c ii and and that Question that inverse question, easy marks to drop :frown:
Reply 10
Thanks very much for posting this. :smile: I agree with all your answers.
Got everything right except the gradient on (2b) where I got -2/(2e-x) ???
Don't know if this is right but even still, should get at least 98 UMS :biggrin: Gonna chill out for Core 4 a bit more now!
Reply 12
Hm, for the simpsons rule i got 3.670. y0 + yn = 0.4656, 4 x odds = 7.9916, 2 x evens = 2.6614. 1/3 x total (11.something) = 3.670
Reply 13
Do you get ECF marks in this?
Estimated grade boundaries?
Reply 15
Original post by Math12345
Wasn't 2a -2/(2e-x)?


Original post by ariamuh
2a) is wrong its supposed to be -2/(2e-x)


****, I did a typo! xD
Reply 16
Error carried forward marks?
Definitely left my calc in degrees for q1. :frown: how many marks will I lose for this? Also for question 5c ii) I also got x values that weren't in the domain but didn't reject them :/. Ah well other than that I agree with this scheme.
Original post by AstusUK
Hm, for the simpsons rule i got 3.670. y0 + yn = 0.4656, 4 x odds = 7.9916, 2 x evens = 2.6614. 1/3 x total (11.something) = 3.670


y0 and yn were both 0. Don't remember the other numbers though
Agree with above but got my own inverse wrong. All others seem correct to me.

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