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Edexcel Mathematics: Core C1 6663 17th May 2017 [Exam Discussion]

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Reply 140
Original post by luciferhf
In short. Once you've found the co-ordinates of the point C, you'll be able to find the gradient of AD.

Then you can just setup an equation to figure out

11 - X = -1
8 - X = 2


coordinates of C is 8 and 10
gradient of AD is 4/3

what next
Reply 141
Original post by luciferhf
P.s. I had my coordinates wrong their.

K has coordinates (8,10) and the gradient of AD is -1/2

y2-y1
===== --> M
x2 - x1

So

10 - X = -1
8 - X = 2


how you got that gradient i think it would be -3/4
Original post by Qer
coordinates of C is 8 and 10
gradient of AD is 4/3

what next

Don't mean to be horrible "luciferhf" but your method really over complicates it.

Qer as long as you know the difference between B and C in terms of X and Y Distances, then you can apply that to (A to D).
Reply 143
Original post by BenSainsbury
Don't mean to be horrible "luciferhf" but your method really over complicates it.

Qer as long as you know the difference between B and C in terms of X and Y Distances, then you can apply that to (A to D).


thanks
one more question if you look its part a to find gradient
AB and BC
gradient of AB=4/3
gradient of BC=-3/4


in mark scheme it shows that it is special case for doing that

it gives gradient AB=-3/4
AND BC=4/3

markschme is also there please look it it if you don't understand what i mean
Original post by Qer
thanks
one more question if you look its part a to find gradient
AB and BC
gradient of AB=4/3
gradient of BC=-3/4


in mark scheme it shows that it is special case for doing that

it gives gradient AB=-3/4
AND BC=4/3

markschme is also there please look it it if you don't understand what i mean

That's not something you have to worry about, as long as you know the perpendicular gradient is -1/m then its fine.

I'm assuming the special case is if someone done 1/m rather than -1/m.
Reply 145
Original post by BenSainsbury
That's not something you have to worry about, as long as you know the perpendicular gradient is -1/m then its fine.

I'm assuming the special case is if someone done 1/m rather than -1/m.


thanks
Reply 146
a) Prove, by completing the square, that the roots of the equation x2 + 2kx + c = 0, where k and c are constants, are k ± √(k2 c).

(4)

The equation x2 + 2kx ± 81 = 0 has equal roots.

(b) Find the possible values of k.


i don't understand how to do part b .
Reply 147
Original post by Qer
a) Prove, by completing the square, that the roots of the equation x2 + 2kx + c = 0, where k and c are constants, are k ± √(k2 c).

(4)

The equation x2 + 2kx ± 81 = 0 has equal roots.

(b) Find the possible values of k.


i don't understand how to do part b .

If there are equal roots then b^2 - 4ac = 0
So (2k)^2 - 324 = 0
So k^2 - 81 = 0
Only solution is when k= +/- 9
(The -81 in the question has no solutions)
Reply 148
the question says y =x^2 -4x +2 not y=x^2 -4x +3 as in your working
Original post by candol
the question says y =x^2 -4x +2 not y=x^2 -4x +3 as in your working


Yes, I realised as soon as I posted.
Can someone explain part ii, answer is 2 btw
Reply 151
Original post by GenjiPro
Can someone explain part ii, answer is 2 btw

You could list the terms till you get the first positive answer.
However a mathematical approach would be to find n when the sequence turns positive and then find the value of that term for that n
so (note: a= -40 from part i)
-40 + (n-1)7 >0
(n-1)7 > 40
7n -7 > 40
7n > 47
n >47/7 so n= 7 (first whole number bigger than 47/7)
now a + (n-1)d
so -40 + (7-1)7
= -40 + 42
=2
As a resit what do you think is the hardest edexcel paper except for June 2016 just gonna do that one to see if I still remember things
Original post by physicsamor
As a resit what do you think is the hardest edexcel paper except for June 2016 just gonna do that one to see if I still remember things


You could try some of the Edexcel Gold papers - they tend to be fairly challenging. Good luck!
Original post by Bubs051213
You could try some of the Edexcel Gold papers - they tend to be fairly challenging. Good luck!


Ah yesI forgot about those ones!thank you :h:
Original post by physicsamor
Ah yesI forgot about those ones!thank you :h:


Original post by Bubs051213
You could try some of the Edexcel Gold papers - they tend to be fairly challenging. Good luck!


you can try the IAL edexcel which is hardeer and challenging- our coming exam will be something based on the IAL
Original post by physicsamor
As a resit what do you think is the hardest edexcel paper except for June 2016 just gonna do that one to see if I still remember things


Are you resiiting C1?
have you done the Qs from by past paper questions by topic from June 2005 to June 2014 for each chapter?
http://www.physicsandmathstutor.com/...s/c1-by-topic/

Edexcel - set 2
it has all the similar qs from each chapter in C1 - all the past paper Qs just for that specifc topic.
Enjoy!
I hope you will find it useful.
Original post by hedork
any predictions?


I think it will be harder than the June 2015 but a bit easier than June 2016
Original post by Shadowfire123
Are you resiiting C1?
have you done the Qs from by past paper questions by topic from June 2005 to June 2014 for each chapter?


Well bear in mind that I'm resitting alongside my a2 subjects lol so I haven't done all the papers at least again (as I did them last year for practise) I have done questions from each topic and like around 4 whole papers but that's all :smile:

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