Edexcel C3,C4 June 2013 Thread

x

The point "P" lies on L1. So you can write the position vector of P in terms of lambda.

Then, the dot product of the direction vector of L1 and the position vector of P should equal 0....

Make sense?

See if you can go on.

Ah sorry! Negged by accident

Urm, while solving a C4 Vector Exercise i've stumbled upon something I have no clue as to what it is.what does it mean to find the ratio in a vector equation?

well this is weird, im finding the soloman papers for C4 easier than the exam papers (based on jan 2013), hope it stays that way ! i've gotten to the stage where im starting to enjoy C4 yep even vectors im really hoping for that A* !!

What's the workload like for French A2? possible to self teach? with AS?

I'm taking a bit of a break from C4/C3 revision in order to revise for M1/S1 in 2 weeks.

How long for? I am tempted to do this for a few days, for D1 and Chem4.5/Phys4.5 Questions, but I am a bit nervous to do so....

Urm, folks I'm having a bit of issue with Solomon Paper B, C3, exercise 3. I have no way of linking at the moment, but I've tried and tried at the exercise for more than 45 minutes, checked the mark scheme and i have no freakin' clue as to how the mark scheme arrived to the answer. Anyone that can help?

The one that asks you to prove the factor formulae?

Expand sin(A+B) and sin(A-B). Then add them both to each other. Then let P = A + B and Q = A - B.

For the second part, use the factor formula that you've just been asked to prove.

Thanks for the reply, but that wasn't the exercise I meant for. Now I'm too confused to even think, my mind is burning.
The exercise i'm having trouble with is in a C4 paper
Yeah found it, Solomon A C4, Exercise 6. It has the angle is 3x and 2x and somehow the markscheme ended with 5x without giving a clue as to how it did that. Sorry for the trouble, I was having trouble with it yesterday night and i fell asleep on it but i moved the papers in my sleep and couldn't remember which one i was doing... these exams are killing me

The one that asks you to prove the factor formulae?

Expand sin(A+B) and sin(A-B). Then add them both to each other. Then let P = A + B and Q = A - B.

For the second part, use the factor formula that you've just been asked to prove.

There's a formula in the formula booklet which should be similar to your problem, can you see how to alter your question now?


Posted from TSR Mobile

Yes! I just found the formula, thanks mate. Man I really have to sit down and memorise all of the damned trigonometric identities, i'm having so much trouble in exercises because i don't know them well

Yes of course its allowed for the exams.
Just check it on ebay. It's available there for $119

Its TI 84
NOT TI 89 (TI 89 is NOT allowed)

I think you lose all the marks for b, but for a you may gain one or two marks.
I would recommend learning this diagram: http://www.thestudentroom.co.uk/showpost.php?p=42319158&postcount=820 makes it so easy to remember differential of sin, cos, -sin and -cos.