AQA A2 Mathematics MM2B Mechanics 2 - Monday 22nd June 2015 [Exam Discussion Thread]

Oh right. Sounds like you've got a large workload! What do you want to do at uni and where?


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Would you say that the content overlapping has helped you with M2?


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Yeah I have a few exams. I'm taking four A2s this year as well, so it totals a lot.

Maths and physics at Bath or Warwick.

It has a lot!

Can I ask, doing M2 as an AS Module, how much C3/C4 knowledge is required for M2 to get a decent grade. Im worried about the stuff on differential equations. The variable acceleration stuff is fine, differentating and integrating trig seems alright, worried about when it comes to log, ln, e etc....

Nice! I wanna do Comp Sci at Bath!


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Can I ask, doing M2 as an AS Module, how much C3/C4 knowledge is required for M2 to get a decent grade. Im worried about the stuff on differential equations. The variable acceleration stuff is fine, differentating and integrating trig seems alright, worried about when it comes to log, ln, e etc....

Ah good! Any tips on revision for it? Any different from C3/C4 preparation?


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That's cool.


As someone who did C4 last year, there is a bit in M2. For differentiation, there are a few rules you have to be able to follow. Integration is the reverse of these.

These rules in M2 will differentiate or integrate an inner function. Choose u as the inner function.
chain rule: $\frac{dy}{dx}=\frac{dy}{du}\frac{du}{dx}$, integration by substitution: $\int y dx = \int y \frac{dx}{du}du$


These are differentials of some common functions that you should remember.
$\frac{d}{dx}(e^x) = e^x$
$\frac{d}{dx}(\sin x) = \cos x$
$\frac{d}{dx}(\cos x) = -\sin x$
$\frac{d}{dx}(x^n) = nx^{n-1}$, when integrating $\int x^n dx = \frac{1}{n+1}x^{n+1}+c$, $x\not{=} -1$
$\int\frac{1}{x}dx+c = \ln x$, $\frac{d}{dx}(\ln x) = \frac{1}{x}$
I believe these are all that are needed for M2, but I might have missed one.

You may also be asked to integrate functions of the form $f(x) = \frac{1}{(x-a)(x-b)}$, so a rational function with two linear factors in the denominator. So integrate this, you must split it up using partial fractions.
Write $\frac{1}{(x-a)(x-b)} \equiv \frac{A}{x-a} + \frac{B}{x-b}$.
Then multiply by the denominator: $1 \equiv A(x-b) + B(x-a)$
Then either multiply out and compare coefficients or substitute x = a and x = b to find the values of A and B. Then you have the original function in partial fraction form, which you can integrate now.


You will be asked to solve first order non-linear ordinary differential equations of the form $\frac{dy}{dx} = f(y)g(x)$, where f and g are functions of y and x respectively.
When solving differential equations, the objective is to find y as a function of x. The general solution has an arbitrary constant (can take any value), but if you substitute initial conditions given in the question, you get the value of the constant and hence a particular solution.
To solve these, you use separation of variables. You can write $\int \frac{1}{f(y)} dy = \int g(x) dx$. You then integrate both sides to get a function of x equals a function of y. When integrating, you only need to add a constant of integration on one side.
Rearrange to get y in terms of x. Then substitute the initial conditions to get the value of the arbitrary constant.


Tell me if you want clarification on anything.

In Mechanics modules the questions are always very wordy, so you need to underline key information. The preparation isn't too different from C3/C4 as questions such as differentiation and integration requires some C3/C4 knowledge as they may bring questions containing exponentials or trigonometry.

Ah right thank you for the pointers! I remember with M1 I prepared slightly differently to C1 and C2 by going through questions in the textbook that were more wordy than pure maths ones. Would you say I should do that again?


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If you find useful, I say go for it. Whatever helps you revise the best, you should do!

Good point - just wondered what others thought! Is it worth revising assumptions from M1?


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I think it would be wise to do that.

Oh good - thanks for all of your help.


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I'm doing M2 with OCR, commenting on this thread because there isn't a thread for OCR. Sorry If I'm intruding

You are very welcome! . I just did the C3 Jan 2012 paper and got 57/75. That was just an A. It was a really diffcult paper. Do you have any suggestions on what I can do to increase my mark average to higher 60s and even 70s?

I'm doing M2 with OCR, commenting on this thread because there isn't a thread for OCR. Sorry If I'm intruding

Hmm yeah I remember that being a hard paper. I would say purely to nail exam technique, attempt it in the way you would do it, then if it's wrong, look at the solution, then re attempt any questions you've got wrong like a day later so that it will test if you've learnt the 'correct' method.


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