You are Here: Home >< Maths

# Edexcel A2 C4 Mathematics June 2015 - Official Thread Watch

1. Thank you so much . I thought I had blown my chances at gettin the B because C3 went awful .
2. (Original post by kingaaran)
No, I'm not asking the first.

But I can't see how that equals , like the person I quoted.

I'm not confused with the identities or how to integrate, I'm sure I'm competent with that, but I'm not sure how ?

Posted from TSR Mobile
They didn't say that? They said
3. (Original post by rayquaza17)
They didn't say that? They said

By implication, this suggests that they are referencing cos^2(y), right?

Posted from TSR Mobile
4. (Original post by kingaaran)

By implication, this suggests that they are referencing cos^2(y), right?

Posted from TSR Mobile
I think monii was incorrect when they said about integrating cos^2(y) because you can actually integrate that, but you don't have to do that in this question. (Sorry monii)

Post 993 has the correct answer for this question.
5. (Original post by kingaaran)

By implication, this suggests that they are referencing cos^2(y), right?

Posted from TSR Mobile
Not sure how well this has come out by hope it's of use.
Attached Images

6. (Original post by rayquaza17)
I think monii was incorrect when they said about integrating cos^2(y) because you can actually integrate that, but you don't have to do that in this question. (Sorry monii)

Post 993 has the correct answer for this question.
To rectify, the only way to integrate is by using the double angle formulae, or is there another 'FP3' method?

Posted from TSR Mobile
7. (Original post by NikolaT)
Not sure how well this has come out by hope it's of use.
Oh, you were talking about the integral of 1/cos^2(y)

Posted from TSR Mobile
8. (Original post by kingaaran)
To rectify, the only way to integrate is by using the double angle formulae, or is there another 'FP3' method?

Posted from TSR Mobile
Yes only sensible way is the double angle formula.
I can think of only one other way to integrate it, but that involves complex numbers which is FP2. Tbh I think the double angle formula is easier in this case.
9. Hi, can anyone tell me how to do 6(a) from Solomon A? The markscheme isn't very helpful. (not sure why 2sin3xsin2x = cosx-cos5x)

Thanks.
10. (Original post by JamGrip)
Hi, can anyone tell me how to do 6(a) from Solomon A? The markscheme isn't very helpful. (not sure why 2sin3xsin2x = cosx-cos5x)

Thanks.
cos(x) = cos(3x - 2x)
cos(5x) = cos(3x + 2x)

Does that help?
11. So I'm thinking I got 69 + method marks on the C3 paper, so what do people think I'll need roughly for the A*? Aiming for low-mid 60s I think to be safe
12. (Original post by RobHunter97)
So I'm thinking I got 69 + method marks on the C3 paper, so what do people think I'll need roughly for the A*? Aiming for low-mid 60s I think to be safe
Depends on the paper bro

Posted from TSR Mobile
13. (Original post by physicsmaths)
Depends on the paper bro

Posted from TSR Mobile
Obviously, but I mean approximately. 50s, 60s etc.
14. (Original post by RobHunter97)
Obviously, but I mean approximately. 50s, 60s etc.
60s
15. (Original post by anonwinner)
60s
Thank you
16. (Original post by kingaaran)
To rectify, the only way to integrate is by using the double angle formulae, or is there another 'FP3' method?

Posted from TSR Mobile
by parts is another way ...
17. Hi, can anyone explain why integrating 6/x is 6lnx and not ln6x? Thanks
18. (Original post by mdc96)
Hi, can anyone explain why integrating 6/x is 6lnx and not ln6x? Thanks
check by differentiation ...
19. (Original post by mdc96)
Hi, can anyone explain why integrating 6/x is 6lnx and not ln6x? Thanks
If you differentiate ln(6x), it becomes 6/6x which cancels to 1/x. Therefore 6x must become 6ln(x) if you integrate
20. (Original post by rayquaza17)
Yes only sensible way is the double angle formula.
I can think of only one other way to integrate it, but that involves complex numbers which is FP2. Tbh I think the double angle formula is easier in this case.
no... you can use integration by parts...in a cunning way

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: April 20, 2016
Today on TSR

### Best unis for graduate salaries

Half of the top 10 aren't even RG...

### My alarm went off in an exam!

Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• Poll
Useful resources

Can you help? Study help unanswered threadsStudy Help rules and posting guidelinesLaTex guide for writing equations on TSR

## Groups associated with this forum:

View associated groups
Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE