Edexcel C3,C4 June 2013 Thread

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tanno1992

Guys I have a problem with my calculator (a normal everyday casio fx-85gt plus). I managed to press a couple of buttons all at once and I don't know what I've done but it's now come up as having TRUE/FALSE at the bottom of the screen. How do I bring it back to normal (and what would I press to bring up this function again (that I never knew existed)). :colondollar:

SHIFT 9 then 3 then = then AC

clears everything!

Reply 3601

06spam

Hey does any one know what shape areas you need to know for c4. will be eternally grateful!!

Reply 3602

Myocardium

Original post by tanno1992

SHIFT 9 then 3 then = then AC

clears everything!

Thanks - I know what I did now :P

Reply 3603

tanno1992

Original post by 06spam

Hey does any one know what shape areas you need to know for c4. will be eternally grateful!!

if you mean formulae then
rectangle, triangle, trapezium, rhombus, parallelogram, kite, surface area cylinder and any others not in the formulae book.
the specification usually lists assumed knowledge

Reply 3604

tanno1992

Original post by Myocardium

Thanks - I know what I did now :P

I got pretty excited when I found this clear function as well. little things huh

Reply 3605

Tikara

has the c3 exam gone?

Reply 3606

May-o2q

Guys, I kno this isn't a good time to talk about C3, but after I read Arsey's answers. I feel so upset about myself. I don't think I would even get a B for this exam. Is there anyone feeling the same thing too? I am just about to burst into tear!

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Reply 3607

Minumi

Original post by Scorcher

Use the identity cos(a) - cos(b) = -2sin(A+B/2)sin(A-B/2)

That's A+B all over 2 and A-B all over 2 btw.

Original post by destinyx

Do cos(3x-2x) - cos(3x-2x) ie. (cox3xcos2x + sin3xsin2x) - (cos3xcos2x - sin3xsin2x) and work it out from there. There are similar questions to this in one of the exercises in the C4 text book. :smile:

I just did this paper the other day so happened to have my method close by. :smile:

Thanks guys! That'll explain why I couldn't figure it out, we never covered the factor formulae in C3. My C3 teacher wasn't the best :unimpressed:

Looks like I'll need to go back to the textbook and practise!

Reply 3608

MyNameIsRay

Original post by 06spam

Hey does any one know what shape areas you need to know for c4. will be eternally grateful!!

square, oblong, trapezium, triangle, parallelogram, circle

I guess that's it.

Reply 3609

ITomI

40/75 marks on the c3 paper would be what ums?

Reply 3610

cooldudeman

Original post by MasterYi

I was trying to say wrong thread.

Here's a physics thread which maybe able to help.
http://www.thestudentroom.co.uk/showthread.php?t=2244676

Haa I'm going crazy.

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Reply 3611

task

can someone explain the how the 3rd line gets to the 4th in this mark a scheme? Q5 b)

thanks
ImageUploadedByStudent Room1371308107.476283.jpg

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Reply 3612

justinawe

Original post by task

can someone explain the how the 3rd line gets to the 4th in this mark a scheme? Q5 b)

thanks
ImageUploadedByStudent Room1371308107.476283.jpg

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\dfrac{x}{2} = 1 - 2 \left( \dfrac{y}{6} \right)^2

\dfrac{x}{2} = 1 - 2 \left( \dfrac{y^2}{6^2} \right)

\dfrac{y^2}{18} = 1 - \dfrac{x}{2}

y^2 = 18 -9x

y = \sqrt{18-9x}

Reply 3613

Westeros

Will I get marked down for using modulus signs instead of brackets when I'm integrating? (With ln functions)

The mark scheme uses brackets and I used modulus signs, does it make a massive difference?

Thanks

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