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

# Edexcel A2 C4 Mathematics June 2015 - Official Thread watch

1. (Original post by 123456789012)
Oh okay, I get it! Thanks a lot!
No worries
2. (Original post by MyNameIsMyName)
Hi.

So basically i wanted to know whether we need to know how to do part B for edexcel spec i haven't really come across those area questions apart from solomon papers.

3. Relative to a fixed origin O, the point A has position vector 3i + 2j – k, the point B has position vector 5i + j + k, and the point C has position vector 7i – j.

(b) Find the exact value of the area of triangle ABC. (3)

Asking us to calculate the area with just 3 position vectors. No lines intersection etc. Just assume the triangle as they all come from 0 so we can draw that. part A was calculate the cosine of triangle ABC pretty straight forward.
Just wanted to know whether part B is in the spec otherwise i wont bother with doing those questions wasting my time. If we need to can someone please give me a good method to do that. 1/2ABsinC etc
Yes That can come up. Since you have the cosine you can get the sine of the angle. Now you can get the distance between each point then use the formula you have quoted. Fin the lengths of the adjacent sides to the angle you worked out.

Posted from TSR Mobile
3. (Original post by physicsmaths)
Og damn i forgot. Quote me later on and ill do it, just doing a past paper rn.

Posted from TSR Mobile
Have you tried the question yet?
4. (Original post by Tow)
Have you tried the question yet?
Ah thanks for reminding. I'll post it in a few minutes.

Posted from TSR Mobile
5. how do you show 2 lines intersect in vectors?
6. (Original post by Tow)
Can you guys help me with a Q?

It's practice paper A2 for C4

This is the question Attachment 407167

I'm stuck on d) :P

I got this:
Attachment 407171

H=A^2/4
H=0.25

Can anyone explain? :P

Posted from TSR Mobile
7. (Original post by studentwiz)
how do you show 2 lines intersect in vectors?
Find value of parameter such that two components are equal then sub into third one and if that is also the same then they intersect, last part is key.

Posted from TSR Mobile
8. can someone explain how 5ln5/4 + 2ln4/5 = 3ln5/4
9. (Original post by studentwiz)
can someone explain how 5ln5/4 + 2ln4/5 = 3ln5/4
Use log laws

Posted from TSR Mobile
10. LOL

I made the most stupid mistake xD

Put wrong numbers in calculator lol

Thanks anyway
11. (Original post by studentwiz)
can someone explain how 5ln5/4 + 2ln4/5 = 3ln5/4

Posted from TSR Mobile
Attached Images

12. (Original post by studentwiz)
can someone explain how 5ln5/4 + 2ln4/5 = 3ln5/4
A few ways to do it

I did the most simple and easy way

13. (Original post by Tow)
A few ways to do it

I did the most simple and easy way

EDIT: did extra working out so you understand
14. Anyone got really hard/challenging questions?

I've done most of the hard edexcel past paper ones so anything else?
15. (Original post by Tow)
Anyone got really hard/challenging questions?

I did most of the hard edexcel past paper ones so anything else?
Tried solomons?
16. (Original post by Gilo98)
Tried solomons?
Don't really wanna do the papers because they're just so different to edexcel.

But are there any hard ones that I could try from Solomon?
17. (Original post by Tow)
Don't really wanna do the papers because they're just so different to edexcel.

But are there any hard ones that I could try from Solomon?
They also do worksheets which I think are good practice - especially for questions like that infamous trig Q on the June 2013 C3 paper. All the solomon papers are 'harder' than Edexcel ones. Might want to also take a look at the 'Gold' edexcel papers
18. (Original post by Tow)
A few ways to do it

I did the most simple and easy way

(Original post by physicsmaths)
Use log laws

Posted from TSR Mobile
Thanks everyone
19. (Original post by Tow)
Don't really wanna do the papers because they're just so different to edexcel.

But are there any hard ones that I could try from Solomon?
I've done the Solomon papers and thought they were really similar to Edexcel - are you sure you're looking at the ones designed for Edexcel specifically?
20. (Original post by Tow)
Anyone got really hard/challenging questions?

I've done most of the hard edexcel past paper ones so anything else?
can you help me on the last part of this question
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: April 20, 2016
Today on TSR

### University rankings 2019

Cambridge at number one

### I have imposter syndrome at Cambridge

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