C3 (Not MEI) - Thursday June 14 2012, AM

Didn't see the thread around so thought I might ad well get this started! :tongue:

How is everyones revising going? What are you revising with? What books have you used? Tips? -just anything C3 OCR related really :h:

I have covered the content to a reasonable extent and done.the mock exam. Didn't do amazing or anything but did okay :smile:

Tomorrow I will go through the C3 book and just try all questions for each of the topics.

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Reply 1

Doctor.

Erghhh, just going through the text book questions there are waaaay too many :angry:

differentiation/integration questions!!! Exponentials messed with my head, then I realised what I was doing :tongue:

Reply 2

Contrad!ction.

Original post by Doctor.

Erghhh, just going through the text book questions there are waaaay too many :angry:

differentiation/integration questions!!! Exponentials messed with my head, then I realised what I was doing :tongue:

Although I'm not taking this exam in summer (did it in Jan) I'm happy to supply worked answers/help on tricky questions from the OCR book or past papers. I've still got my books/papers lying around somewhere so I can take photos and annotate answers if you'd like me to.

Reply 3

Doctor.

Original post by Contrad!ction.

That would be awesome, there isn't many I messed up on (thankfully), I will get them up tomorrow :h:

Thanks again!

Reply 4

Contrad!ction.

Original post by Doctor.

That would be awesome, there isn't many I messed up on (thankfully), I will get them up tomorrow :h:

Thanks again!

I probably won't be posting pictures until late afternoon tomorrow (school has a filter system) but I could always type stuff out and LaTeX stuff up.

I find the formula book's generally useful, in C3 and 4 especially. For cos 2x and sin 2x, you don't have to remember anything as you can just let A and B = x and use the formula for cos(A+B) or sin(A+B). The integration/differentiation section's also pretty useful as it saves you spending ages deriving results they already give. Also, the quotient rule's in there.

Reply 5

Doctor.

Original post by Contrad!ction.

Decided to do C3 tomorrow noww! So hopefully will put up the questions I cant do then :smile:

Thanks again, really do appreciate the help :h:

if I do manage to pull off an A/A* in maths I am giving you guys £100 each :tongue:

and a:

!!

(minus the £100 I'm broke! :ninja:

)

Reply 6

Contrad!ction.

Original post by Doctor.

Decided to do C3 tomorrow noww! So hopefully will put up the questions I cant do then :smile:

Thanks again, really do appreciate the help :h:

if I do manage to pull off an A/A* in maths I am giving you guys £100 each :tongue:

and a:

!!

(minus the £100 I'm broke! :ninja:

)

I've got pretty much all the exam questions answered properly, so I should be good to help you. I won't have worked solutions for Jan's exam, but I answered them all when I sat the exam so I should be able to get those done too. What areas in particular are your weakest? Might see if I can find some resources or some decent tricks for different types of question.

This is my C3 section of the wall, ignore how it says C4. Those things are pretty handy to remember - although some of it can be derived using the formula booklet, it can make it easier to spot things and means you can work through things quickly.

I might have to hold you to that :wink:

...dammit.

Reply 7

Doctor.

Original post by Contrad!ction.

I have come to the conclusion that you have wooden flooring in the room/corridor next to your room :holmes:

oh and your notes are pretty awesome! :tongue:

C3...It's weird,in the Jan '12 mock I checked with Mr M's answers and I dont 'think' I got anything wrong. Maybe if I upload my exam sheet and the paper you could just have a quick look and see If I went wrong anywhere?
(don't want you spendibg hours making a worked answers sheet just for me :colondollar:

)

I don't think I struggle much...LOL Transformstions :facepalm:

Almost as bad as when i integrate instead of differentiate :s-smilie:

I will go through the misc questions tomorrow and post up my incorrections :smile:

oh and the C3 mock :tongue:

lol i bet i made 100s of mistakes in the mock but just pretend they dont exist. I do that a lot :lol:

(edited 11 years ago)

Reply 8

Contrad!ction.

Original post by Doctor.

I have come to the conclusion that you have wooden flooring in the room/corridor next to your room :holmes:

oh and your notes are pretty awesome! :tongue:

)

I don't think I struggle much...LOL Transformstions :facepalm:

Almost as bad as when i integrate instead of differentiate :s-smilie:

I will go through the misc questions tomorrow and post up my incorrections :smile:

oh and the C3 mock :tongue:

lol i bet i made 100s of mistakes in the mock but just pretend they dont exist. I do that a lot :lol:

Nope, a crappy carpet.

Do it - I'll need to see the paper, but I should be able to see any issues. I hope your handwriting isn't as bad as mine.

I'd make revision cards with the transformations on them - so one side says 'y=f(x-a)' and the other says 'translation, a units, positive x direction', for example. I am, actually. I'm taking C1 again in June and helping a friend with her retake as well.

Yeah, do that :smile:

It'll be interesting to see how much I can remember :laugh:

'+k? Yeah, I know that should be there. Benefit of doubt mark'll do'... oops.

...actually, I don't have any of: Jan 09, Jun 09, Jan 10, Jun 10, Jan 11, so if you need help with those I'll need to see the question too.

Reply 9

Doctor.

Original post by Contrad!ction.

It'll be interesting to see how much I can remember :laugh:

http://s1262.photobucket.com/albums/ii604/Hayley_Cassells/ My question paper for C3

Reply 10

Doctor.

The questions I cannot do: :frown:

(so far, lol there's bound to be more :cry:

)

They're attached and thank you :h:

(edited 11 years ago)

Original post by Doctor.

The questions I cannot do: :frown:

(so far, lol there's bound to be more :cry:

)

They're attached and thank you :h:

For 3)b):
From a,

\sec^2 x - \tan^2 x=1

Generally, if part of a question gets you to 'state' or 'show that', one of the next parts will use it. That is the case here.

\sec^2 x - \tan^2 x=1

can be expressed as the difference of two squares. See if this helps you.

For 7:

\int e^x \ dx = e^x + C

Unparseable latex formula:

\int e^-^x \ dx = -e^-^x + C

Generally,

Unparseable latex formula:

\int e^f^(^x^) \ dx = \frac{1}{f'(x)} e^f^(^x^) + C

Bung the limits in, rearrange and it should come out right. Might need a bit of manipulation, and if you get stuck, just quote me back in.

Will post with next couple in a min.

(edited 11 years ago)

Reply 12

Contrad!ction.

2):

Rate of decay: 12% per hour. After each hour, there is 0.88% left from the hour before. So the proportion =

0.88^r

. See if you can finish this one off.

5's asterixed, so it's not on the syllabus. I could have a go, but it's waffly. For the first part, you'd plot the values and chuck on a line of best fit. Should show exponential growth. To find a, find where the line crosses the y axis - t will = 0, so y=a. Then you can use another point to find b. b) will use your a and b values from a).

Reply 13

Contrad!ction.

13) When you complete the square, you can easily see the range of a graph's equation. The stuff outside the bracket is the range, so once you've completed the square, you'll have something outside the bracket which should equal -7.

8 a and b, plus the extra bit) You'll have to work backwards. Undo everything. So reflect it back in the x direction, unstretch, and then move it in the opposite direction.

2b) - is that two b or not two b? :wink:

from a, translation, 3 units, positive y direction and translation, 1 unit, positive x direction.
Again, it needs undoing. Try to apply the same idea from 8).

(edited 11 years ago)

Reply 14

Doctor.

Original post by Contrad!ction.

For 3)b):
From a,

\sec^2 x - \tan^2 x=1

Generally, if part of a question gets you to 'state' or 'show that', one of the next parts will use it. That is the case here.

\sec^2 x + \tan^2 x=1

can be expressed as the difference of two squares. See if this helps you.

For 7:

\int e^x \ dx = e^x + C

Unparseable latex formula:

\int e^-^x \ dx = -e^-^x + C

Generally,

Unparseable latex formula:

\int e^f^(^x^) \ dx = \frac{1}{f'(x)} e^f^(^x^) + C

Bung the limits in, rearrange and it should come out right. Might need a bit of manipulation, and if you get stuck, just quote me back in.

Will post with next couple in a min.

3b: isn't it,

\sec^2 x - \tan^2 x=1

which can be the diff of two squares? :s-smilie:

(\sec x - \tan x) (\sec x - \tan x)=1

Confused on this one sorry :frown:

I get the integral part of 7, I think its the re-arrangement!

Not too sure how I would get the integral (e^x + e^-x) to the corrct one :s-smilie:

(edited 11 years ago)

Reply 15

Doctor.

Original post by Contrad!ction.

2):

Rate of decay: 12% per hour. After each hour, there is 0.88% left from the hour before. So the proportion =

0.88^r

Got the first one now lol, it wasnt that bad :facepalm:

thank you

No chance am I going to do that one...I always thought the asterisk meant it is just really hard :lol:

Reply 16

Doctor.

Original post by Contrad!ction.

from a, translation, 3 units, positive y direction and translation, 1 unit, positive x direction.
Again, it needs undoing. Try to apply the same idea from 8).

13: I forgot about the outside being equal to the range, got It now :tongue:

8: I still dont understand how to exactly get started. Just complete the square and start from there? :s-smilie:

2b:I got it! I guess 8 is comp sq then :smile:

Thank you!

only a few more chapter to go now :biggrin:

Reply 17

Contrad!ction.

Original post by Doctor.

3b: isn't it,

\sec^2 x - \tan^2 x=1

which can be the diff of two squares? :s-smilie:

(\sec x - \tan x) (\sec x - \tan x)=1

Confused on this one sorry :frown:

I get the integral part of 7, I think its the re-arrangement!

Not too sure how I would get the integral (e^x + e^-x) to the corrct one :s-smilie:

Ah *******s, yeah it is. I noticed the first one and corrected it, didn't realise that I'd still left one in. I copied the LaTeX for the sin² identity and didn't change the signs.

Difference of two squares: a²-b²=(a+b)(a-b). That better?

Show me what you get when you put the limits in.

Reply 18

Contrad!ction.

Original post by Doctor.

13: I forgot about the outside being equal to the range, got It now :tongue:

8: I still dont understand how to exactly get started. Just complete the square and start from there? :s-smilie:

2b:I got it! I guess 8 is comp sq then :smile:

Thank you!

only a few more chapter to go now :biggrin:

8's the same as 2, unless I'm looking at a different question to you.

Say a person wants to give you a present. They'll put it in a box, apply wrapping paper and then tie a bow on it. You'll take the bow off (undo step 3), remove the wrapping paper (step 2) and then take it out of the box (1). It's the same principle as algebra, really.

What they do:
Translate 2 units, negative x direction
Stretch, y direction, factor 4
Reflect in y axis

What you have to do:
Reflect back in y axis
Undo the stretch: stretch, y direction, factor 1/4
Undo -2 units x translation: +2 units, x direction

So the first transformation takes