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OCR Core 3 Jan 2013 question 6 help

Hi guys I really need help with Question 6 part 4.


What I did was change y=ln(x) to y=4ln(x-2)
and then changed y=8-2x2 to y=4(8-(x-2)2)

and then tried to equate them and got an iterative formula. When I looked at the mark scheme, it said to use the answer of part 3 which i got to be 1.917 to get the value of 3.92. Using the iterative formula, if i put in 1.917 i get 3.27.
my iterative formula is the square root of 4+4x-(lnx/ln2)

Please could you show me where I am going wrong or break down the question for me?
thank you very much for your help, I really do appreciate it.
Reply 1
Please, anyone?
I also need help with Question 9 part 1, i cannot prove it :s-smilie:

Here is the question paper guys sorry
(edited 10 years ago)
Reply 2
Original post by HEY_101
Please, anyone?
I also need help with Question 9 part 1, i cannot prove it :s-smilie:

Here is the question paper guys sorry


You're over complicating Q6 (iii)

Rather than actually changing the equations of the curve, use the fact that the original curves are moving.

BOTH curves move 2 to the right, and so will the point of intersection.

Also as both curves are stretched with SF 4 in the y direction, surely all you need to do is find the original (y coord) for the point of intersection and times it by 4?

-------

Q9 (i)

Taking a picture is easier than typing it so hopefully you can read it

OSAfZsX.jpg
(edited 10 years ago)
Reply 3
Thanks so much for question 9!

But I'm still stumped for question 6 part 4

So the point of intersection is 1.917 on x, and so 0.65 on y,
both graphs move 2 in the x direction so it becomes 3.917 on x and then (0.65*4) which is 2.6


OMG THANK YOU!!!
(edited 10 years ago)
Reply 4
Original post by HEY_101
Thanks so much for question 9!

But I'm still stumped for question 6 part 4

So the point of intersection is 1.917 on x, and so 0.65 on y,
both graphs move 2 in the x direction so it becomes 3.917 on x and then (0.65*4) which is 2.6


OMG THANK YOU!!!


sounds right :smile:
Reply 5
Original post by HEY_101
Please, anyone?
I also need help with Question 9 part 1, i cannot prove it :s-smilie:

Here is the question paper guys sorry


Hey do you have the mark scheme for the JAN 13 C3 Paper?
Reply 6
Original post by ForevaDoc
Hey do you have the mark scheme for the JAN 13 C3 Paper?


HEY sorry just saw this now, i dont think it will be useful now would it?

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