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OCR MEI FP2 Thread - AM 27th June 2016

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[QUOTE="Aph;66137879"]the limit as
Unparseable latex formula:

n\rightarrow\infty[\latex][br]was [latex]\frac{1}{7}\begin{pmatrix} 3 & 4 \\3 & 4 \end{pmatrix}[/latex][br]right?



Yeah thats what I got
Reply 141
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Aph
22
Original post by decombatwombat
Yeah thats what I got

thanks...
no idea what the issue with my latex is though...
Original post by ComputerMaths97
For the M^n = PD^nP^(-1)
When you multiplied out the matrices, aren't you supposed to do the two on the right first? Might have messed that up badly too.


Matrix multiplication is commutative or however you say it (that might not even be the right word I just remember it from FP1) so A x B x C = (A x B) x C = A x (B x C)
Reply 143
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leaf3
1
Original post by ComputerMaths97
For the M^n = PD^nP^(-1)
When you multiplied out the matrices, aren't you supposed to do the two on the right first? Might have messed that up badly too.


It shouldn't make a difference?
Forgot +c for the arctan
Messed up the first part of 2, realised c+js was the expansion of (1-ejtheta)^n but couldnt get any further
I think i did the right method for the last question but got 5ln((3+root5)/2) - a string of surds.
The rest i did right, how many marks do you think?
I left my answer for polar question as 0.5a^2ln8 didnt simplify the half and ln8, will i lose a mark?
Original post by decombatwombat
Matrix multiplication is commutative or however you say it (that might not even be the right word I just remember it from FP1) so A x B x C = (A x B) x C = A x (B x C)


Original post by leaf3
It shouldn't make a difference?


You guys are legends, that's exactly what I thought but I can't remember getting the same matrix as others (3,4,4,3 clockwise) for M^n as n tends to infinity, maybe I did, but I was trying to figure out my mistake.

*I totally knew that, I'm just clearly having an awful day loool*
Original post by betapro
I left my answer for polar question as 0.5a^2ln8 didnt simplify the half and ln8, will i lose a mark?


Highly doubt it, you should be okay.
Original post by decombatwombat
Highly doubt it, you should be okay.


K thanks, didnt it ask for it in simplest form tho?
Original post by betapro
K thanks, didnt it ask for it in simplest form tho?


Yeah but I think that was referring to the 2pi divided by pi/4.
Reply 150
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Aph
22
Original post by betapro
K thanks, didnt it ask for it in simplest form tho?

I'd argue both are as simple a eachother.
Reply 151
Avatar for BriO
BriO
1
M^n= was 4 3
................4 3
all divided by 7
as n tends to infinity
I just checked on a matrix calculator. It's also what i got.
(edited 7 years ago)
Original post by betapro
K thanks, didnt it ask for it in simplest form tho?


Simple in mathematics tends to refer to the number of operations.

So by multiplying the whole ln expression by a half, you've done just as many *extra* operations that square rooting the value inside the expression before taking its natural log.

That's how I see it at least.
Original post by BriO
M^n= was 4 3
................4 3
as n tends to infinity
I just checked on a matrix calculator. It's also what i got.


Can you show some subsequent working because that seems to ring a bell for me but I could do with some extra info :smile:
Anyone able to do an unofficial mark scheme? I gotta revise for Physics tomorrow, would really appreciate it some does one and I get linked/ tagged to it :biggrin: I've already done 2 unofficial mark schemes for this year I cba to do anymore plus I better revise :biggrin:
Reply 155
Avatar for BriO
BriO
1
Original post by ComputerMaths97
Anyone able to do an unofficial mark scheme? I gotta revise for Physics tomorrow, would really appreciate it some does one and I get linked/ tagged to it :biggrin: I've already done 2 unofficial mark schemes for this year I cba to do anymore plus I better revise :biggrin:


I'll show some working in a sec. How you feeling about physics? The grade boundaries are always so low I love it
It seems with the exception of the last part of the past Q, I'm good.

I got 10ln((3+root(5))/2) but couldn't get the second part of its equation. Taking into account any silly errors & there goes my firm.

GG, MEI wins:colonhash::colonhash:

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For the matrix one, did you actually have to write PD^nP^-1 for your marks or was it just referring to the form of the matrix?? I didnt write any PDP^-1 but wrote out my matrices like that if you get me haha
Reply 158
Avatar for BriO
BriO
1
Original post by ComputerMaths97
Can you show some subsequent working because that seems to ring a bell for me but I could do with some extra info :smile:


Fp2.png (done in paint xd)

Again, any online matrix calculator confirms. Just put in M and raise to like power 10.
I think I plotted the points on my Argand diagram too small, but you can definitely see it in the paper. Will it get scanned ?

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