Current Year 12 Thread Mark VI

Teach me the ways, haha. So annoyed about Physics today!

STEP Philosophy time.

Did you also fail the practical today? WJEC?

I'm not sure whether discussing it violates the exam discussion rules. I will say that (my paper) was pretty difficult. I'm sure I could have done better usually, but my graph was just horrendous The fact that 100% UMS is ~~45/48 just makes me cringe, I hope that doesn't cost me an A :/

Urgh! Sorry - I had to do some menial chores.



I assumed that it was too obvious that $4 \times 2^k$ was divisible by 8, so I said that it was divisible by 8, without rearranging it to make it $8\times 2^{k-1}$ first. Not even a proper mistake.



Once I learn some more F.Maths it will be. I haven't tried any yet. I have looked aat them but I haven't attempted them.



Huzzah! Just done STEP I 2004 Q1. It's probably the most straightforward STEP question I have ever done.

I'll see if I have any interesting questions.

I found it easy, but i ran out of time in section B, all because i did the experiment properly and didn't make up my results, so I didn't get to calculate my gradient or do basically the last page, think i got full marks in section A though.

Advanced extension award. It used to be available for most subjects until a*s were around. It still is available for maths. It's an extra, harder exam that you can sit.

Wcp beat me to it.

http://www.edexcel.com/quals/gce/aea/9801/Pages/default.aspx

Huzzah! Just done STEP I 2004 Q1. It's probably the most straightforward STEP question I have ever done.

Oh dear....rookie error

Okay

That question I did in a maths lesson as it was set by my teacher. It took 15 mins tops. That was with distractions...

How did you solve the simultaneous equations for (ii)? It took me 2 sides of A4 of fiddling and substituting and factorising I'm guessing there was probably an easy method I missed.

Ah, well it could have gone worse.

Section B stumped most of my class as well. 45mins is no where near enough time to do all of those readings + repeats + Changing the apparatus + calculations + plotting the graph + doing the questions to follow.

Especially compared to Chem and Biology, where there is essentially unlimited time to do the prac, and you can look at your notes mid way through! And then the physics marks are higher for good UMS

Lol, I think everyone needs to nail ph2 now. Luckily most of it is very nice.

Thanks.

So is that for A2 candidates?

TRIAL AND ERROR (which is a valid method). Like a baws.

You see, I am always looking for the quickest ways of doing such things - loads of extra unnecessary stuff does not interest me (maybe I'm just too lazy). I took one look at those simultaneous equations and thought: "No way am I going to do fiddly manipulations to solve these! " So, I looked at the question and it said that $c$ and $d$ were positive integers, so I took the easier looking simultaneous equation and tried reasoning sensible values that $c$ and $d$ could take. I got the correct values on the first attempt.

(click that face to see the derivative)

Too much fail for me today, I should have realised immediately that c^3 < 99 and 2d^3 < 70. Which leaves around 6 possibilities for each if they are positive integers. Bah, bad day

...

nice integration question $\int \frac{1}{\sqrt{3-2x^2}}\ dx$

nice integration question $\int \frac{1}{\sqrt{3-2x^2}} dx$

I got the first one to sum to:

$\frac{2\cos \theta - \cos^2 \theta -\sin theta}{(2-\cos \theta)^2 + sin^2 \theta}$

Which probably simplifies....but I need to do my physics I'll have a look again later

Let $u = \sqrt{2} x$. Then $\displaystyle \frac{du}{dx} = \sqrt{2}$

Therefore $\displaystyle \int \frac{1}{\sqrt{3-2x^2}} dx = \int \frac{1}{\sqrt{3-u^2}} \ \frac{dx}{du} du$

$\displaystyle = \int \frac{1}{\sqrt{3-u^2}} \times \frac{\sqrt{2} }{2} \ du$

$\displaystyle = \frac{\sqrt{2} }{2} \int \frac{1}{\sqrt{3-u^2}} \ du$

$\displaystyle = \frac{\sqrt{2} }{2} \left(\arcsin \left( \frac{u}{\sqrt{3} } \right) \right) + c$

$\displaystyle = \frac{\sqrt{2} }{2} \arcsin \left( \frac{\sqrt{6} }{3} x \right) + c$

Dayumn... wcp got there quicker.