You are Here: Home >< A-levels

# Edexcel Core 4 Thursday 12th June watch

1. (Original post by bongo fury)
why does cot^2 2x = cosec^2 2x -1 ?
derived from sin^2x plus cos^2x = 1
2. Its just a trig identity that you just learn.

I think it derieves from cot x = cosx/sinx and then doing alot of fancy stuff I cant quite remember.
3. (Original post by bongo fury)
why does cot^2 2x = cosec^2 2x -1 ?
divide cos^2 x + sin^2 x= 1 by sin^2 x and subtract 1 from each side
4. Oh i see. Thanks
5. Please could someone explain how to do Question 4 (i) from the January 2008 paper?

It asks you to integrate ln (x/2)

I got xln1/2x - 1/12x^3

But I don't think I have done it right.
6. (Original post by [email protected])
Please could someone explain how to do Question 4 (i) from the January 2008 paper?

It asks you to integrate ln (x/2)

I got xln1/2x - 1/12x^3

But I don't think I have done it right.
Do it by parts and say that it is 1*ln(x/2)
and so 1st*integral of second - integral of (differential of the first * integral of the second)

this is then xln(x/2) - integral of (1/2x / 1/2x)
so the final answer is xln(x/2) - x + c
7. whaaaaaaaaat?! how do you integrate lnx?????
8. u = lnx, dv = 1

solve from there
9. oooh thanks!
10. Personally I learn that Int of lnx is xlnx - x + c but I know how to prove it just in case

Do you still get all marks if you get the answer right these days? Can't remember how edexcel marking works..
11. How do you do 5a). on the C4 jan 2008? I factorise it, but i get y^2 - 24y - 128 = 0 Are there any solutions for this?
12. http://sohanshah.webs.com/mathsasalevel.htm

13. i'm done for. C4 will be the death of me
14. Hmm I've completely skipped vectors and cba to learn it at this point in time , I still figure I can get 75% + raw marks, does that warrant an A for C4 in UMS?
15. I thought 80% was an A... but not completely sure...
16. Christ im nervous about this exam. Its like they took all the hardest stuff you could possibly do in A level maths and stuck it in one rotten module. I hate it

at least I wont have to do maths ever again after tomorrow, about time to be honest
17. What are the best parts to learn to get a mid D in this module. I.e. easiest way to ensure a D?

Actually better make it a C just in case.

I'm scared.
18. (Original post by Trif)
What are the best parts to learn to get a mid D in this module. I.e. easiest way to ensure a D?

Actually better make it a C just in case.

I'm scared.
Vectors, partial fractions, binomial expansion are all the easiest bits. Differentiating by parts is quite easy as well.

I'm really struggling with differential equations
19. I cant do differential equations half the time, cause they always seem to turn it into some page long essay with only 2 useful bits of information in it and my brain gets all confused
20. cann someone plzzz tell me. if (3u^2 +3)/2 . the same as 3u^2 + 3/2

and if so how. . january 2006 paper question 3. stuckk at simplification LOL.

sorryy . basic algebra problemsss ..

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: June 13, 2008
Today on TSR

### TSR Pub Quiz 2018 - Anime

The first of our week-long series of entertainment quizzes

### University open days

Wed, 21 Nov '18
• Buckinghamshire New University
Wed, 21 Nov '18
• Heriot-Watt University
Wed, 21 Nov '18
Poll

## All the essentials

### Student life: what to expect

What it's really like going to uni

### Essay expert

Learn to write like a pro with our ultimate essay guide.

### Create a study plan

Get your head around what you need to do and when with the study planner tool.

### Resources by subject

Everything from mind maps to class notes.

### Study tips from A* students

Students who got top grades in their A-levels share their secrets

## 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