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

# Edexcel C3,C4 June 2013 Thread watch

1. (Original post by Theafricanlegend)
why isnt it 3^-xln-3?
y = -3 ^ (-x)
ln y = - ln 3 ^-x
ln y = x ln 3
1/y dy/dx = ln 3
dy/dx = (-3 ^ (-x) * ln 3)

although it should be positive ....
2. How do you find the coords minimum/maximum of a curve? I know you differentiate and equate to 0, but how do you find one if there is a both a minimum and a maximum? If I remember correctly, it should come out with two results, and the negative one is the x coord of the maximum?
3. (Original post by Rayquaza)
Still stuck :/
expand the brackets and if you sub it back into the original equation what do you get? it should be pretty straightforward now..
4. (Original post by zzz.)
alot of people are saying the c4 paper is gnna be worse than the C3 ppr!!!

But your comment made me happy.. What makes you think that though??
I doubt the paper would be that hard, remember Edexcel would have listened to the recent criticism from the C3 paper.

It depends on when the C4 papers were delivered to the schools. If they were delivered a couple of days after the c3 exam, then it wouldn't be such a hard paper!

Remember to stay positive and do your best! That's the only thing you can do
5. (Original post by kuku2013)
hey thanks, I don't understand from the 5th step!! why do you have to make it all into ln(2)?
I turned it into ln2, so that I can factorise it out.
6. (Original post by ACBLISS)
integration
Okay well I'd use the substitution of U = X^2 and that should then equate it down rather nicely
8. Going to head off now. Good luck for tomorrow everyone!
9. (Original post by MathsNerd1)
Just remain calm as if you've covered everything then that's all you can do, now getting a good nights rest before the exam would be very advisable by myself as you'll be both physically and mentally prepared
Thanks
10. Can anyone confirm if we have to integrate x/1+x . = x-ln(x+1) ?
11. (Original post by Kreayshawn)
can someone tell me what shapes we need to know the area/volume of?
i've asked a few times but no response, don't wanna have to skip a whole question on the exam because i don't know the area/volume of something basic
This is largely off the top of my head, somebody correct me if I've missed anything. As you can see, most of them are very simple. The only tricky ones, I think, would be the volume of a cone (1/3 * base * height), and area of a regular shape (which will almost definitely not come up).

2D areas
• Circle/semicircle
• Rectangle
• Triangle
• Any regular shape (although they would have to give you a hint)

3D volumes
• Sphere/hemisphere
• Cuboid
• Cone (for any base)
• Prism (cylinder is the most likely one to be asked for)

3D surface areas
• Cuboid
• Err...

You are given these by the formulae booklet (in the C1 section)
• Surface area of a sphere
• Surface area of a cone
12. (Original post by Story)
Can anyone confirm if we have to integrate x/1+x . = x-ln(x+1)
This is what I got
13. (Original post by Theafricanlegend)
hint: ..
14. Is it just me or is June 12 really nice? Please please c4 paper, be like that D:
15. (Original post by MathsNerd1)
Only on the questions that ask you to use substitution but I'm saying that I'll use the technique when trying to integrate the ones that can be done by recognition so I need to work out a suitable substitution first
Ohh I see why not just do the integration by recognition? or do you mean to check your answer?
I think you can do it on the graphical calculators I remember doing c2 integration and differentation, but it takes abit of time - is good to check your answer though.
16. (Original post by Jullith)
Going to head off now. Good luck for tomorrow everyone!
17. Is there a way of knowing how to separate variables in differential equations?
18. (Original post by ACBLISS)
oops the first one
pfft, easy one then

Spoiler:
Show

20. (Original post by justinawe)
pfft, easy one then

Spoiler:
Show

I got this via a substitution then by parts, that's the type of thing I'd like to appear tomorrow where you've got multiple steps to 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

### Loughborough better than Cambridge

Loughborough at number one

### Can I date a girl with no boobs?

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