x Turn on thread page Beta
 You are Here: Home >< Maths

# Edexcel C3,C4 June 2013 Thread watch

1. (Original post by tsr1)
c3- jan 2007 -question 8iia)

given that: y= arcosx

-1 < x ≤ 1 and 0 ≤ y ≤ pi

express arcsin in terms of y

can anyone help with this? really stuck.. thanks
The exam solutions link will show you the answer, but I did it differently.

arccos(x) = y
so cos(y) = x

now, assuming you know that cos(x) = sin(90-x) [and also that sin(x)=cos(90-x), though not relevant in this case] you know that:

sin(90-y) = x

and hence arccsin(x) = 90-y
2. (Original post by justinawe)
Generally, the domain would be everything except for the value that makes the denominator equal 0, and the range would be anything other than 0.

Of course, it can depend on additional information given in the question as well.

Is there not an algebraic method?
3. (Original post by überambitious_ox)
Find the exact value of x such that

3arctan (x-2) + pi =0

Please can someone explain how this would be solved. Thank you

Hope this is right...

Posted from TSR Mobile
4. (Original post by überambitious_ox)
Find the exact value of x such that

3arctan (x-2) + pi =0

Please can someone explain how this would be solved. Thank you

3arctan(x-2) + 180 = 0
3arctan(x-2) = -180
acrtan(x-2) = -60
x-2 = tan(-60)
x-2 = -root3
x = 2 - root3

That's what I got anyway, not sure of the actual answer.

Edit: Looks like I've been beaten to it
5. (Original post by MathsNerd1)
It will be due but just remember they are reflections in line y=x so it's not too hard really
Yer I think theyre ok, but not the nicest questions in the world, especially back in 2007! Apart fro that, theres nothing in the content that strikes me as something 'bad'.
6. (Original post by suncake)

Hope this is right...

Posted from TSR Mobile
Thank you; yes it is
7. Apparently c3 was leaked and the replacement is way harder !!!

Posted from TSR Mobile
8. (Original post by Flounder1)
Apparently c3 was leaked and the replacement is way harder !!!

Posted from TSR Mobile
Why would it be harder? Why not just a different paper?
9. (Original post by Flounder1)
Apparently c3 was leaked and the replacement is way harder !!!

Posted from TSR Mobile
I call bs
10. (Original post by Flounder1)
Apparently c3 was leaked and the replacement is way harder !!!

Posted from TSR Mobile
Source?
11. (Original post by ApplePearOrange5297)
I call bs
No, the papers were stolent/leaked/lost, it's on the edexcel website. It affected C3, C4 and some others. I don't see why they'd be harder, though. Just a different paper.

Edit: https://fbcdn-sphotos-a-a.akamaihd.n...77688065_n.jpg
12. Can anyone help me with this quick problem?

The question states

f: ln(x+k)
g: |2x-k|

Evaluate fg(k/4)

I got that fg = ln(2x-k+k) = ln2x = ln2k/4

Simplifies to lnk/2

HOWEVER, the markscheme says that the answer is ln3k/2?
13. Hows everyone feeling about tommorow ? :/ did anyone else make loads of silly mistakes in jan that made them miss the A by 1 mark :/ errh retakes
14. (Original post by Flounder1)
Apparently c3 was leaked and the replacement is way harder !!!

Posted from TSR Mobile
Yeah i heard about that too. Just hope theyre nice to us. The c4 paper got leaked too
15. (Original post by physicso)
Can anyone help me with this quick problem?

The question states

f: ln(x+k)
g: |2x-k|

Evaluate fg(k/4)

I got that fg = ln(2x-k+k) = ln2x = ln2k/4

Simplifies to lnk/2

HOWEVER, the markscheme says that the answer is ln3k/2?
What papers this from ?
16. (Original post by physicso)
Can anyone help me with this quick problem?

The question states

f: ln(x+k)
g: |2x-k|

Evaluate fg(k/4)

I got that fg = ln(2x-k+k) = ln2x = ln2k/4

Simplifies to lnk/2

HOWEVER, the markscheme says that the answer is ln3k/2?
f(k/4) = |-k/2| = k/2 sub this into f(x) and BOSH!
17. (Original post by BearOfStown)
Source?
http://www.thestudentroom.co.uk/show....php?t=2362486

And I'm guessing the source of that is the edexcel website.

Yes, there's a replacement paper but this doesn't mean it will be harder. As edexcel have said, the replacement papers have gone through the same processes as the originals, and are no harder/easier than the original papers.

So there really isn't anything to worry about.

Edit:

And if you don't believe edexcel, and still think they'll give a harder paper, the FP1 replacement paper was done on Monday, and most candidates found it (fairly) easy. So I doubt they'll screw you guys over

Good luck!
18. (Original post by kingpro88)
Hows everyone feeling about tommorow ? :/ did anyone else make loads of silly mistakes in jan that made them miss the A by 1 mark :/ errh retakes
that is gutting! first time ive taken the paper and feeling confident
19. C3 is going to be so much Banter. I can't wait for it.

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: September 24, 2013
Today on TSR

### Four things top students are doing

Over the Easter break

### Her parents made her dump me

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

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