You are Here: Home >< Maths

# Edexcel C2 20th May 2015 *Official Thread* watch

1. (Original post by coefficient)
In the first line they are splitting up that power to get 1^ x / 3^x and 1^x = 1 so it's just 1/3^x. They then multiply both sides by 3^x.
This gives 1 = 2 * (3^x) * (3*x)
We then divide by two to get (3^x)^2 = 1/2
we then take log of both sides and bring down the power 2x to get 2xlog(3)=log(1/2).
We then divide by log3 to get 2x = log(1/2) / log(3) and then divide by 2 to get the final answer
Thankss
2. Good luck guys.

Posted from TSR Mobile
3. (Original post by jshep000)
Hopefully, will be bless if we don't get one of those crappy weird questions at the end haha.
probably will unfortunately haha
4. (Original post by jshep000)
It still works, it just gives you a negative value. Our teacher taught it to us, that if r>1 than we had to swap it and do r-1.
It won't give a negative value (unless the terms are negative) as the denominator is swapped as well. As you can see in the proof, the two formulae give the exact same answer and they are purely conjugates for ease of use:

5. Just out of curiosity, when a given range for trigonometric questions, includes >= or <=, do we include the values they're equal to as angles? Like 0 <= x <= 180, is 180 included as an answer?
6. What is an A for the June 2013 R paper?
7. (Original post by Skygon)
Just out of curiosity, when a given range for trigonometric questions, includes >= or <=, do we include the values they're equal to as angles? Like 0 <= x <= 180, is 180 included as an answer?
Yes, because it means "less than or equal to 180" and not "less than 180".

8. (Original post by coefficient)
Because sometimes if we start in year 2000, it's easier to call that year 0 than year 1. Really it's just people who are more confident saving time. There's no real benefit of it, it's just being fancy.
Or just do what I do and count the value of n on your finger if you are confused as to what n might be and use ar^(n-1). Haha I know we went past finger counting at primary school but it still helps to avoid confusion.
9. (Original post by TrentL)
thank you very much Abbey and yes that would be amazing!
took me a while :/
Attached Images

Thanks! (also please could you show all your working as to how you got the answer if possible)
11. (Original post by Da Di Doo)
What is an A for the June 2013 R paper?
64 for an A
57 for a B
12. goodnight people. best of luck tomorrow!
13. we get 1 , n, nc2, nc3, for the ncr coefficients and then accending powers of kx.

If the coefficient of are equal then:

1/2 = (n-2)/6 * k
3 = k(n-2)
14. Any tips on circles at all

Posted from TSR Mobile
15. I reckon the paper will be quite chill tbh, C1 had some strange worded questions for some people. So they probably were nice and gave us a good C2 paper <3
16. (Original post by Shanahey)
Thanks! (also please could you show all your working as to how you got the answer if possible)
Use the other method for binomial expansion the n(n-1)/2! Method from formula booklet and see if you can work it out

Posted from TSR Mobile
17. (Original post by Shanahey)
Thanks! (also please could you show all your working as to how you got the answer if possible)
when A=4 then
18. Besides sequences in c2, what else do we have to be able to prove the formula for?
19. Somebody needs to help me with optimisation
20. (Original post by Skygon)
Besides sequences in c2, what else do we have to be able to prove the formula for?
I might be wrong but I rarely ever see a question asking to prove a formula?

Posted from TSR Mobile

### Related university courses

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: May 15, 2017
Today on TSR

### Edexcel C3 Maths Unofficial Markscheme

Find out how you've done here

### 3,799

students online now

Exam discussions

### Find your exam discussion here

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