The Student Room Group

Edexcel A2 C4 Mathematics June 2016 - Official Thread

Scroll to see replies

How did everyone do 4b (to find the time of decay) and 8e (find coordinates of e).
Anyone else done now? Feels so weird not having to revise!
Unofficial mark scheme in about 30-45 mins when I'm home
can anyone reemebr the marks allocated and the questions?
i know this much

1 binomial expansion - (5marks)
2
3
4 decay a) solve dx/dt = -5/2x in terms of x and t (4 marks) b) x=60 to 20, find t (for this i got ln(60)=c) and 234 minutes (4makrs)
5
6
7 integrate (2x-1)^3/2 (2 marks) b) coordinate of k (3/4marks) c)volume of S (7marks)
8 vectors a) find a , b) equation of l2, c) d) e)area of triangle
Original post by psychemma
0.5 x 2root2 x 2root2 x sin(30 something)

I can't remember the value of the sin but it's whatever cos(4/5) is


You get a 3,4,5 triangle so sin(theta) = 3/5
Original post by ryanroks1
Wasn't it 60e^-2.5t?


No because it was 1/3= e^-2.5t and so you flip it over
Original post by sadych
pretty sure my volume was 512pi -(1024/5)pi, left it as this as was rushing


I got this too
Original post by cjlh
My full solutions:

1) 1/8 - 15/16 x + 75/16 x^2 - 625/32 x^3

2) 0.6595, 1.083, 8/3 ln(2) - 7/9

3) (-2-4xy)/(2x^2 + 4 + pisin(0.5pi)), (3pi+62)/(pi+22)

4) x=e^(ln(60)-2.5t)), 633 mins

5) (-5root(3)/16), (4,5root3)

6) 3ln(3y+2)-2ln(y)+c, lambda=8, 4pi/3 - root3

7) k=17/2, 1696pi/5

8) {3,5,0}, r = {1,5,2} + lambda{-5,4,3}, k=2, cos(theta)=4/5, area=12/5, possible positions {3, 33/5, 16/5} and {-1, 17/5, 4/5}

I GOT EXACTLY THE SAME IM SOO HAPPY, hope they're right tho
Original post by kkboyk
I got this too


Fairly certain this is correct as it simplifies to 1696/5 pi
Reply 4090
Original post by sadych
pretty sure my volume was 512pi -(1024/5)pi, left it as this as was rushing


I got 512pi-(10245)pi as well...
That was lovely, though I didn't get the last part of Q8
Reply 4092
How many marks is the last question (coordinates of E)?
How many marks would I lose for getting the wrong lambda for 6 then using it for the last part?
fml got everything else right but totally ****ed question 8
Original post by NamelessPersona
Fairly certain this is correct as it simplifies to 1696/5 pi


Now that i think about it yea it does, since the volume of the cylinder had pi :eek:
Original post by hollycooper_1
can anyone reemebr the marks allocated and the questions?
i know this much

1 binomial expansion - (5marks)
2
3
4 decay a) solve dx/dt = -5/2x in terms of x and t (4 marks) b) x=60 to 20, find t (for this i got ln(60)=c) and 234 minutes (4makrs)
5
6
7 integrate (2x-1)^3/2 (2 marks) b) coordinate of k (3/4marks) c)volume of S (7marks)
8 vectors a) find a , b) equation of l2, c) d) e)area of triangle


8f) finding the points of E was worth 5 marks
Sick exam, curbstomped it
ohh wtf that was a cylinder
Anyone else get a=4/3 and b=-rt3 the last part of question 6? (i think it was this question)...

Quick Reply

Latest