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

# Edexcel C3,C4 June 2013 Thread watch

1. (Original post by OneMorePanda)
Good luck integrating .
Actually I would make my u= e^x^2

And dv= 6x

Posted from TSR Mobile
2. (Original post by justinawe)

Differentiating both sides w.r.t x:

Sorry, no...Still lost. Like a cow on Astroturf.
3. (Original post by nm786)
no don't expand it.
How come? Is that a general rule for differential equations?
4. (Original post by nm786)
now expand the brackets and integrate.
Hmm interesting i would tackle this q in a different much longer method lol im skacking in my speed of recognizing identities:/
5. (Original post by nm786)
now expand the brackets and integrate.
What if it was 1/sin^2(x)cos^2(x) ?

Posted from TSR Mobile
6. (Original post by justinawe)

Differentiating both sides w.r.t x:

can you not use the integration by parts straight away?
7. Did anyone get to the point where there was not enough time to attempt every single question on every single edexcel paper from several years ago and every soloman paper, so decided to just do the hard questions instead?

I.e. leave out implicit diff and binomial and partial fractions and anything else that looked doable enough
8. (Original post by SortYourLife)
Isn't that just (1/2x) e^x^2 ? :s

Posted from TSR Mobile
No, you could differentiate that to see that it isn't.
9. (Original post by OneMorePanda)
Good luck integrating .
Lol im so undercooked atm how do you integrate that :/
10. (Original post by OneMorePanda)
No, you could differentiate that to see that it isn't.
Oh yeah :') you'd just use substitution wouldn't you?

Posted from TSR Mobile

11. QQ how would you split the above into partial fractions?
12. (Original post by überambitious_ox)
Did anyone get to the point where there was not enough time to attempt every single question on every single edexcel paper from several years ago and every soloman paper, so decided to just do the hard questions instead?

I.e. leave out implicit diff and binomial and partial fractions and anything else that looked doable enough
exactly what I'm doing lmao - although I'm mainly just focusing on the big integration questions :P
13. when u get to the point where u have (0.5sin(2x))^2 u just use the double angle formula of cosine and then u integrate
14. (Original post by Rayquaza)
Book shows to integrate by substitution but I'm lost.
What don't you understand du=2x dx

Posted from TSR Mobile
15. If you times an integral (with limits) by -1 do you swap the limits?
16. (Original post by SortYourLife)
Oh yeah :') you'd just use substitution wouldn't you?

Posted from TSR Mobile
Yeah.

(Original post by Myocardium)

QQ how would you split the above into partial fractions?
I'm not sure if it's called partial fractions, but you can write the x in the numerator as x - 2 + 2.

(Original post by Tikara)
If you times an integral (with limits) by -1 do you swap the limits?
Yeah.
17. (Original post by Myocardium)

QQ how would you split the above into partial fractions?
you just add and subtract two! so x+2-2/x-2
and this gives you 1+(2/x-2)
18. (Original post by Tikara)
exactly what I'm doing lmao - although I'm mainly just focusing on the big integration questions :P
ahaaa so it's not just me
19. (Original post by Rayquaza)
Sorry, no...Still lost. Like a cow on Astroturf.
Suppose that was a guess to the answer to the integral. To check if its right, you differentiate it to see if you get . You get instead. Its not exactly what you need, but its almost identical. How can you change the initial guess so when you do differentiate you get .

Alternatively, a substitution of . Its a longer way, but if you're more comfortable with it, then its the better way.

(Original post by Myocardium)

QQ how would you split the above into partial fractions?
20. (Original post by Myocardium)

QQ how would you split the above into partial fractions?
long division, hope this helps,
Attached Images

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