Edexcel C4 June 2014- OFFICIAL THREAD

Hey, if anyone could help me with part B of this question that'd be great (it's from the original paper last year). I've got as far as getting a general solution to the equation, but I'm confused at Arseys solution and really confused about whether or not there needs to be a '+c'

Thanks




Posted from TSR Mobile

You do not need +c, and you put 100 on the bottom of the integral and 50 on the top as it says the time taken for the depth to decrease FROM 100 to 50, you can then times by -1 and put 100 on the top and 50 on the bottom so it looks like a typical integral

Is the answer 707?

For A why did he remove the 27? Also whenever i type it into my calculator from the 3sec^2 t /(blah blah) i get 1/18 for the gradient


Posted from TSR Mobile

Right, two past papers completed in timed conditions today, two solid As. I'm not going to try my luck and do a third, just a little more clearing up mistakes here and there and then I'm taking the night off Having a calculator that can do numerical integration is such a life saver in terms of being able to check your answers and not lose your mind during the exam.

Is everyones c4 exam in the afternoon?

Nope, mine is on the 19th. I'm gonna memorise Arsey's solutions and score 100 UMS ^_^ Yeah, it's tomorrow afternoon for everyone :P

Yeah but some people have other exams plus in my school we were told if we wanted to do c4 earlier we could..
if we had another exams on the same day..

He's wrong. The answer will be ln2*2^x

General rule if you prefer parroting is a^x ===> ln(a)*a^x (I think, in the exam you must show working)