Edexcel A2 C4 Mathematics June 2015 - Official Thread

yup I don't understand why AS and A2 timings are the same for maths?

guys do u know how to handle
integral of : sin3xcosx ??

am i the only one who feels that there's never enough time to finish a standard paper in the 1hour 30 mins that has been given? or am i not just fast enough?

guys do u know how to handle
integral of : sin3xcosx ??

I got that but I still am not getting the correct answer :9

guys do u know how to handle
integral of : sin3xcosx ??

Do you think they might ask volume of revolution around the y-axis? I can't remember them ever asking that?

Nope, it's not in the spec

Came up in an Edexcel Specimen Paper

How would you do it then just in case? Integrate πx² in terms of y instead?

Came up in an Edexcel Specimen Paper

for x=2
sec() = 2
cos() = 1/2
() = pi/3

for x=3
sec() = 3
cos() = 1/3
() = arccos(1/3) in radians

Could someone please explain to me part b of this expansion question from June 2013 R it's a simple element but I really don't understand it! Thanks

Well, you've expanded 8-9x cube rooted, and you're asked to find the cube root of 7100. So you ask yourself how you can make 8-9x look anything like 7100. Well, x=1/10 makes it 7.1, so using the expansion you get the cube root of 7.1. But we want the cube root of something a thousand times bigger.

Just like (2*4)^2 = 8^2 = 64 = 4*16 = 2^2 * 4^2, the cube root of 7100 can be split into the cube root of 7.1 and the cube root of 1000 multiplied together. So you get the expansion for 7.1 and multiply by the cube root of 1000, which is 10.