* Honours Maths Paper 2 " Let's fight back :)

Daniel S

canister94 wrote: »

eq of tangent of circle x1x+y1y=r squared
angle between two lines tan theta=m1-m2 over 1=m1m2
perpendicular distance
cosine rule
cos a+b = cosacosb - sinasinb
difference equations un=la power of n +mb power n
all your trig proofs then but they are main ones

If we know all them, are we sorted, and are there any others that could possibly come up? Spending all day today learning every proof!

After yesterday.... I need to do good.

GV_NRG

ladytwink wrote: »

Just joined boards having been similarly SCREWED over by maths paper 1 (my strongest out of the 2 papers by far!!!:( Just wondering if anyone could explain the
"cos a+b = cosacosb - sinasinb
difference equations un=la power of n +mb power n"
thoerums or has a link showing them?.. especially the second one please!..
Best of luck to every1 on Mon...judging by paper 1 we're gonna need it!

you along with about 500 other people joined boards.ie after yesterday :P

hunii07

mtb_kng wrote: »

If we know all them, are we sorted, and are there any others that could possibly come up? Spending all day today learning every proof!

After yesterday.... I need to do good.

I'm doing the exact same... might do Irish too if I get time

PJelly

Quick silly tangent slope question...
You know how the quick way to get the slop of a tangent is -B/A?
Well, I thought that the X is always taken as A. So.. 3x-2y+y=o would have a slope of 2/3
But I've got y-2x=0. So I re-arranged it to make 2x-y=0 (multiply across by a minus) so I had a slope of 1/2. But the slope is 2. So they took A as Y and B as X.

Are you not able to multiply across by a minus in a tangent? Does that mess up its location completely?

canister94

i hae those proofs as document cant upload them

cocopopsxx

ladytwink wrote: »

Just joined boards having been similarly SCREWED over by maths paper 1 (my strongest out of the 2 papers by far!!!:( Just wondering if anyone could explain the
"cos a+b = cosacosb - sinasinb
difference equations un=la power of n +mb power n"
thoerums or has a link showing them?.. especially the second one please!..
Best of luck to every1 on Mon...judging by paper 1 we're gonna need it!

Here are some - Proofs
Not all the proofs are there, but it might help.

PJelly

canister94 wrote: »

i hae those proofs as document cant upload them

Take screenshots and upload those.

Daniel S

cocopopsxx wrote: »

Here are some - Proofs
Not all the proofs are there, but it might help.

A girl definatly wrote out those proofs anyway! Girliest handwriting I've seen in ages!

canister94

erwf.jpg here it is

epicwinning

luciemc wrote: »

anyone doing question 9?

My class didn't do it but I'll probs try it anyway. Got 26/50 in the Pre in it which is more than what most people were getting for the circle question (and did a victory lap by getting 50/50 in Q8)

cocopopsxx wrote:

Thanks a million! I appreciate the help, thanks! xx

No probs .

GV_NRG

PJelly wrote: »

Quick silly tangent slope question...
You know how the quick way to get the slop of a tangent is -B/A?
Well, I thought that the X is always taken as A. So.. 3x-2y+y=o would have a slope of 2/3
But I've got y-2x=0. So I re-arranged it to make 2x-y=0 (multiply across by a minus) so I had a slope of 1/2. But the slope is 2. So they took A as Y and B as X.

Are you not able to multiply across by a minus in a tangent? Does that mess up its location completely?

do it as Y=Mx + c

you have 2x-y=0

-y=-2x

y=2x
but y=Mx

therfore M=2 i hope ive awnsered your question :P

PJelly

GV_NRG wrote: »

do it as Y=Mx + c

you have 2x-y=0

-y=-2x

y=2x
but y=Mx

therfore M=2 i hope ive awnsered your question :P

So that's the preferred approach when you have a Y by itself?
Thanks loads!:D

canister94

PJelly wrote: »

So that's the preferred approach when you have a Y by itself?
Thanks loads!:D

minus the coefficient of x over coefficent of y is the easiest

epicwinning

canister94 wrote: »

minus the coefficient of x over coefficent of y is the easiest

Ah yes, it's easy to mix this up with the Sum of the Roots formula...

PJelly

canister94 wrote: »

minus the coefficient of x over coefficent of y is the easiest

.... That's a much more sensible way to approach it, than "-B/A"
Thank you too

God these maths are so relaxing. After yesterday I'd almost forgotten what it feels like to get questions right. Paper 1 almost killed my spirit. Almost.

GV_NRG

PJelly wrote: »

So that's the preferred approach when you have a Y by itself?
Thanks loads!:D

i never knew there was another way to do it? that is the way ive always done it :O

PJelly

epicwinning wrote: »

Ah yes, it's easy to mix this up with the Sum of the Roots formula...

*facepalm*
That's what I was doing.

Patriciamc93

The circle tangent proof:
B part i
http://www.studentxpress.ie/papers/circlesoln2008.pdf

The perpindicular distance:
C
http://www.studentxpress.ie/papers/linesoln2008.pdf

Measure of angle between two lines
C part I
http://www.studentxpress.ie/papers/linesoln06.pdf

Difference equation:
B
http://www.studentxpress.ie/papers/probsoln2010.pdf

I will put of the trig ones in a min.

canister94

i have all proofs on computer i said earlier .if ya want any of them pm an i will upload. i need to get off because i need to study

spazzy

epicwinning wrote: »

My class didn't do it but I'll probs try it anyway. Got 26/50 in the Pre in it which is more than what most people were getting for the circle question (and did a victory lap by getting 50/50 in Q8)


eh you can't do both 9 and 8!

PJelly

For those that need to brush up on identities..
http://www.mathsireland.com/LCHGeneralNotes/Trig/Comp_Angle_Form/Prov_Trig_Iden_1.htm

Shayanzadeh

PJelly wrote: »

.... That's a much more sensible way to approach it, than "-B/A"
Thank you too

God these maths are so relaxing. After yesterday I'd almost forgotten what it feels like to get questions right. Paper 1 almost killed my spirit. Almost.

It's -A/B not -B/A. So in your 2x-y=0 you would get 2 as slope. Easy to mix up with -B/A which is from alpha + betha.

PJelly

Shayanzadeh wrote: »

It's -A/B not -B/A. So in your 2x-y=0 you would get 2 as slope. Easy to mix up with -B/A which is from alpha + betha.

It's clearly not my day.

epicwinning

spazzy wrote: »

epicwinning wrote: »

My class didn't do it but I'll probs try it anyway. Got 26/50 in the Pre in it which is more than what most people were getting for the circle question (and did a victory lap by getting 50/50 in Q8)

eh you can't do both 9 and 8!

Highest one counts. I'd thought I messed up Q8 completely so I did Q9 as an extra question in the 3-ish minutes I had left in the exam.

Shayanzadeh

PJelly wrote: »

It's clearly not my day.

Don't worry, wasn't my day yesterday either. Made some stupid mistakes. Getting the hard bits right but not the easy bits

spazzy

epicwinning wrote: »

Highest one counts. I'd thought I messed up Q8 completely so I did Q9 as an extra question in the 3-ish minutes I had left in the exam.

oh sorry i thought you meant instead of the circle or one of your others
fair play

hunii07

PJelly wrote: »

It's clearly not my day.

Relax we all have days like that...:) unfortunately I had one of those yesterday

josephdaly111

Can they ask difference equations outside the probability questions?

PJelly

Don't sob about yesterday!
This is the paper 2 thread, this is the future! Be positive.
I kept thinking on how badly I did on paper one, even the simple bits, but it's over and no amount of moping will change it.

kpac

I was going to say the difference equation wouldn't come up because it appeared last year, but after yesterday I wouldn't rule out anything.