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Graph question (2 marks)

Hi can someone explain/ go through how you would go through a question like this? :smile:

Thanks.

question 12.png

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Reply 1
I've had a crack at the first 2. I'm not sure though

I solved the equation for y to get x and got 4 and -4.

Therefore A is (-4,0) and B is (4,0)

For the second part I used the distance formula... and got 8.


For the 3rd part... I'm thinking to use dy/dx........
When I use it, I then put in -4 for the x value to get the deepest point
Reply 2
Original post by StanKing
I've had a crack at the first 2. I'm not sure though

I solved the equation for y to get x and got 4 and -4.

Therefore A is (-4,0) and B is (4,0)


For the second part I used the distance formula... and got 8.


For the 3rd part... I'm thinking to use dy/dx........
When I use it, I then put in -4 for the x value to get the deepest point


That bold part is correct, how did you solve it? :smile:
Reply 3
Ah, well, I expanded out the brackets (forget about the y=) and got

3x^2/16 - 3.

Then I made it equal to zero and got 3x^2/16=3

Times the 16 by the 3 to get 3x^2=48

Then divided both sides by 3 and got x^2=16

Therefore x=(+-)4 :smile:
Reply 4
Original post by StanKing
Ah, well, I expanded out the brackets (forget about the y=) and got

3x^2/16 - 3.

Then I made it equal to zero and got 3x^2/16=3

Times the 16 by the 3 to get 3x^2=48

Then divided both sides by 3 and got x^2=16

Therefore x=(+-)4 :smile:


Thanks for that :biggrin:
Reply 5
Original post by StanKing
I've had a crack at the first 2. I'm not sure though

I solved the equation for y to get x and got 4 and -4.

Therefore A is (-4,0) and B is (4,0)

For the second part I used the distance formula... and got 8.


For the 3rd part... I'm thinking to use dy/dx........
When I use it, I then put in -4 for the x value to get the deepest point


For part 3 (iii) you use integration, but can someone go through it please?
Thanks. :smile:
Original post by blueray
For part 3 (iii) you use integration, but can someone go through it please?
Thanks. :smile:
To find area you always integrate for curves.

Let me handwrite tit and then i will type up my method.
Reply 7
Original post by GreenLantern1
To find area you always integrate for curves.

Let me handwrite tit and then i will type up my method.


Cheers!
Original post by blueray
Cheers!


Omg I just spent 20 mins typing it up in latex then when I went to press preview post for like the 10th time to check it was alright. The ****ing Internet randomly went now it is all gone!!! :rant:

I am actually pissed off!!!!

Basically, though just take the 3/16 out of the integrand and have it as a fraction. And change lower limit to 0 since it same as uppe rand times final answer ar 2. Simple as that!!
Btw could you please senfd me the specimen addmaths paper file as i do not have access to that.
Reply 10
Original post by GreenLantern1
Omg I just spent 20 mins typing it up in latex then when I went to press preview post for like the 10th time to check it was alright. The ****ing Internet randomly went now it is all gone!!! :rant:

I am actually pissed off!!!!

Basically, though just take the 3/16 out of the integrand and have it as a fraction. And change lower limit to 0 since it same as uppe rand times final answer ar 2. Simple as that!!


Umm could you type up the latex on microsfot word then post it here so if the internet goes at least it's on notepad or word :frown: SOrry I didn't understand a word you said!

Sure I can give you the papers pm me :biggrin:
Original post by blueray
Umm could you type up the latex on microsfot word then post it here so if the internet goes at least it's on notepad or word :frown: SOrry I didn't understand a word you said!

Sure I can give you the papers pm me :biggrin:


Ir would take so long to type it out again and I have to revise. Do you not have a markscheme to it.
Reply 12
Original post by GreenLantern1

Basically, though just take the 3/16 out of the integral and have it as a fraction. And change lower limit to 0 since its same as upper and times final answer (ar) 2. Simple as that!!



so [3/16] 4 on top and 0 on bottom? then times by 2??? Have you got a scanner or a camera can you take a pic of what you did on paper and upload it?

Or email me :smile: When you are free, cuz I know you're revising :smile:
Reply 13
Original post by GreenLantern1
......


so [3/16] 4 on top and 0 on bottom? then times by 2??? Have you got a scanner or a camera can you take a pic of what you did on paper and upload it?

Or email me When you are free, cuz I know you're revising
Original post by blueray
so [3/16] 4 on top and 0 on bottom? then times by 2??? Have you got a scanner or a camera can you take a pic of what you did on paper and upload it?

Or email me When you are free, cuz I know you're revising


I will have to email tomorrow with a picture of my working out mate!
Reply 15
Original post by GreenLantern1
I will have to email tomorrow with a picture of my working out mate!


It's cool bro :biggrin: I did it!
Original post by blueray
It's cool bro :biggrin: I did it!


Lol late much bro?
Reply 17
ROFL ^
Reply 18
Original post by GreenLantern1
Lol late much bro?

Did it to get your attention (look bellow :tongue:

Original post by Azland
ROFL ^


Can you do this green? :biggrin:

http://www.thestudentroom.co.uk/showthread.php?t=1984928
Original post by blueray
Did it to get your attention (look bellow :tongue:



Can you do this green? :biggrin:

http://www.thestudentroom.co.uk/showthread.php?t=1984928


Yes I can indeed.

I see how to do it. Just do 1 - [P(O)+P(1)].

Can't actually do it though now - in the middle of the Cambridge Chemistry Challenge

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