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AQA Mathematics GCE, A2, 24th January 2011 MPC4

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Reply 40
Original post by ibysaiyan
MU ?


The greek letter. I'm talking about the vector question. Mu=1, or 5/7? I went for 5/7, as the shape was a trapezium, not a parallelogram.

http://en.wikipedia.org/wiki/Mu_(letter)
Original post by Lox352
The greek letter. I'm talking about the vector question. Mu=1, or 5/7? I went for 5/7, as the shape was a trapezium, not a parallelogram.

http://en.wikipedia.org/wiki/Mu_(letter)


IDK but the final answer needed was coordinate C (27,x,x)
Original post by Lox352
The greek letter. I'm talking about the vector question. Mu=1, or 5/7? I went for 5/7, as the shape was a trapezium, not a parallelogram.

http://en.wikipedia.org/wiki/Mu_(letter)


I think Mu=1 as AB.AD=AB.BC which worked out to Mu=1
Reply 43
Original post by toxp
I got 54 for that question as well, it came out as 53.15 which I think you round up? The wording of the question confused me.


Yeah, that's what I got! :biggrin: Nice to know that I have three marks then...

I didn't mind the wording of it so much, but some questions on papers in the past have been horrendously-put, to the extent that I've not had a clue if they were asking this or that. They should bear in mind that maths people don't tend to be any good with words :awesome:
Reply 44
Original post by toxp
hmm I cant remember sorry. did m0/100=m0*2^(-t/8) and solved for t i think.


Just realised tom, i did all that but did 1/10 not 1/100 so got 26 DAMN IT! Thats 3 marks aswell what a waste:angry:
What did people get for the partial fractions/binomial expansion question?
Reply 46
Original post by jaydemikaela
What did people get for the partial fractions/binomial expansion question?


A=3 B=-6

And I think I mucked up the expansion. Can anyone remember the exact question?
Reply 47
Original post by kerily
Yeah, that's what I got! :biggrin: Nice to know that I have three marks then...

I didn't mind the wording of it so much, but some questions on papers in the past have been horrendously-put, to the extent that I've not had a clue if they were asking this or that. They should bear in mind that maths people don't tend to be any good with words :awesome:


I agree lol

Original post by J0e
Just realised tom, i did all that but did 1/10 not 1/100 so got 26 DAMN IT! Thats 3 marks aswell what a waste:angry:


That sucks, you should get method marks though.
Reply 48
Original post by Lox352
A=3 B=-6

And I think I mucked up the expansion. Can anyone remember the exact question?


I got this too! :biggrin:

I can't remember what I got exactly, but there was a -23/50 in there somewhere, and I thought it was valid between -3/5 and 3/5. :smile:
Reply 49
Original post by Lox352
The greek letter. I'm talking about the vector question. Mu=1, or 5/7? I went for 5/7, as the shape was a trapezium, not a parallelogram.

http://en.wikipedia.org/wiki/Mu_(letter)


That's what I got!!!

I went through it with my teacher afterwards and he agreed.
If you go with myu as 1 then comes out with nice numbers but the wrong shape.

Myu = 5/7 gives you horrible fractions but the correct shape.
Original post by Lox352
The greek letter. I'm talking about the vector question. Mu=1, or 5/7? I went for 5/7, as the shape was a trapezium, not a parallelogram.



I got this, after a ridiculous amount of working, and got C as (64/7, -18/7, 65/7) or something like that.
The only thing I definitely got wrong is using degrees instead of radians after the differential equation (stupid) and maybe that last vectors one isn't right, we'll see
Reply 51
Original post by kerily
I got this too! :biggrin:

I can't remember what I got exactly, but there was a -23/50 in there somewhere, and I thought it was valid between -3/5 and 3/5. :smile:


Yep, agree with the validity range.
Original post by kerily
I got this too! :biggrin:

I can't remember what I got exactly, but there was a -23/50 in there somewhere, and I thought it was valid between -3/5 and 3/5. :smile:


Ah crap I think I put 5/3 :facepalm:
Reply 53
Original post by jaydemikaela
Ah crap I think I put 5/3 :facepalm:


(a + x)^n is valid provided -a < x < a, so (3 + 5x)^-1 is valid provided -3 < 5x < 3, which is -3/5 < x <3/5. :smile: If you did it in stages, you may well get the first mark; if you just put 5/3, I think that may well be two marks gone :frown:
Original post by kerily
(a + x)^n is valid provided -a < x < a, so (3 + 5x)^-1 is valid provided -3 < 5x < 3, which is -3/5 < x <3/5. :smile: If you did it in stages, you may well get the first mark; if you just put 5/3, I think that may well be two marks gone :frown:


Tbh I can't really remember what I wrote. It was definitely one or the other :tongue:
Reply 55
Ahhhhhh think I lost max 10 marks. Damn the vector question.... I thought it was quite hard actually, anyone else? :P
Reply 56
1) R=root29, a=28.1?

2)(3x+1)(3x-1)(x+2)=f(x)
3x[3x-1]^-1
p=-9

3)3(1+x) -6(3+5x)
1+x/3 -23x/9
-0.6<x<0.6

4)2e^t/3 + 2/3e^3t so 4/3
3y + 12 =4x
K=9

5)about 3
d=32
53.16 => n=54

6)...
X = tan^-1(+-root3) so 60,120
->2sin^2x + 2sinx -1=0
sin x isn't <-1 so 0.5(root3 -1)=Sinx

7) x=(2-cos0.5t)^2
9metres
3.6seconds at 5metres

8) AB=(6,0,3)-(3,-2,4)=(3,2,-1)
85.9deg
D:frown:3,-2,4)+2(2,-1,3)=(7,-4,10) so l2=(7,-4,10) + MU(3,2,-1)
And lastly:
|AD|=root56=|BC|
so (1+3MU)^2 + (2MU-4)^2 + (7-MU)^2 = 56
so MU=1 or 5/7.
MU =\ 1 because |DC|=\|AB| so MU=5/7
thus C:frown:64/7,-18/7,65/7)
Reply 57
Original post by vladtheimpaler
I got this, after a ridiculous amount of working, and got C as (64/7, -18/7, 65/7) or something like that.
The only thing I definitely got wrong is using degrees instead of radians after the differential equation (stupid) and maybe that last vectors one isn't right, we'll see


I also got that exact coordinate! Thats a relief haha! Fancy checking my other answers above? :wink:
Reply 58
Original post by rob...
1) R=root29, a=28.1?

2)(3x+1)(3x-1)(x+2)=f(x)
3x[3x-1]^-1
p=-9

3)3(1+x) -6(3+5x)
1+x/3 -23x/9
-0.6<x<0.6

4)2e^t/3 + 2/3e^3t so 4/3
3y + 12 =4x
K=9

5)about 3
d=32
53.16 => n=54

6)...
X = tan^-1(+-root3) so 60,120
->2sin^2x + 2sinx -1=0
sin x isn't <-1 so 0.5(root3 -1)=Sinx

7) x=(2-cos0.5t)^2
9metres
3.6seconds at 5metres

8) AB=(6,0,3)-(3,-2,4)=(3,2,-1)
85.9deg
D:frown:3,-2,4)+2(2,-1,3)=(7,-4,10) so l2=(7,-4,10) + MU(3,2,-1)
And lastly:
|AD|=root56=|BC|
so (1+3MU)^2 + (2MU-4)^2 + (7-MU)^2 = 56
so MU=1 or 5/7.
MU =\ 1 because |DC|=\|AB| so MU=5/7
thus C:frown:64/7,-18/7,65/7)


Yep, aside from a few typos, I think I agree.
Reply 59
Original post by Lox352
Yep, aside from a few typos, I think I agree.


We I obviously didn't put smilies in my exam if that's what you mean haha. Which ones though, those typos may not actually be typos :frown:

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