C3 Jan 11 Edexcel - Solutions and Paper in the first post (Now On) + TIPS

Hi Arsey just wonderign if you cna help me out with this and see if this is a correct method

Say if they ask Cos(A+B) in the form of P+Q/2 .

Is this write way to do it:

Cos(A+B)=CosACosB-SinASinB
Cos(A-B)=CosACosB+SinASinB Add them together

you get 2cosAcosB P=A+B Q=A-B

A=P+Q/2 B=P-Q/2
And then how do do you know what P and Q are for example if it was something like cos5x+cos20x.
Also If this method is correct does it work for others like Sin(A+B) Cos(A-B) cheers!

Anyone know where I can get the June 10 paper from please? Edexcel website says it's not available yet...

Does anyone have a markscheme for C3 July 2010, or can someone talk me through question 7. d)?

Thanks,

Tory88

rearrange the equation to make the modulus equation the subject.

Then split them into two separate equations

f(x) = ...... and - f(x) = .....

then solve both

BUT REMEMBER to check to see if both solutions are valid, by drawing the graph

Anyone know where I can get the June 10 paper from please? Edexcel website says it's not available yet...

U got there b4 me Lol.

Where's Arsey and his tips?!?! xD

sketching has only come up once before but the last question on Jan 07 was about arcSin and arcCos

Solve: 3xe^7x+2=15 (5) - January 2010

This question was so disgusting, I felt sick

Can anyone help me with this question:

Using the identities for sin(a+b) and cos(a+b), prove that:

tan2a= (2tana)/(1-tan^2 a)

Here it is June 2010 C3. I have to upload an unoffical MS as the one I have is too big.