Edexcel A2 C4 Mathematics June 2015 - Official Thread

What does it mean by 3(d) ? Find the ratio AC:CB I have the values of lambda for all of the co-ordinates


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I need help with this one

I need help with this one

I am trying to find equation of normal to a line (question inserted) and I have managed to answer it using gradient vector method. Is my method is correct(answer attached)? Also is it okay to leave line equation in column vector form?

I have tried a 2nd method for the question using dot product but I am blank about how to find an expression for the direction of the perpendicular line. In my attempt I tried to find coordinates of a point on the normal line but that seems the wrong way(working attached). Somehow a dot product method seems impossible here to me. Would someone help?

Hey guys,

I need some advice- I am at the stage now where I pretty much understand all of c3 and c4 and the only place I lose marks is through silly mistakes eg. Using t=pi/6 instead of pi/4 in the question . It's just that I make a lot of these silly mistakes so I was wondering if anyone had any tips on improving on this


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Has everybody already been hitting C4 Past papers?

I must be late because I'm only starting them today and plan on getting x1 past paper done each day
leading until my mock next week. My class has just barely finished learning the content for core 4.
Is anybody else in the same boat?

Btw, when did TSR update the theme colour & post options.

I have the same problem so the only thing that helps me is to redo the paper at least twice in the hopes of spotting at least one of those mistakes, although that's not too efficient either.

Posted from TSR Mobile

The general method you used is correct, but C is a point on the line through AB, so you can express this as: (3-2t)i+(5+5t)j. You can then follow through with your method, there will be only one unknown and then you can solve for it, and form an equation as usual.
Hope it clears it up!
(In this post I assume we are working with i and j components)
P.S. Are these questions in the C4 Edexcel book - if not, were did you get them from?

Well for the second question since we are dealing with directions we can compensate for some scalar parameter by setting one of rhe componenets as 1 namely the z component as this is usually the convenience. Now you have two equaltions which shoukd be solvable. I think this is the problem you are encountering, if this is not the case let me know and I will try my best to answer your question.


Posted from TSR Mobile

Can you just clarify if the spaces mean that the vectors are equal


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do you mean the position vector of c will be given by (3-2)I + (5+5t) j? I attempted this here but once again I am blank

This question is from the longman edexcel book

spaces? Nah those are probably blanks left due to photocopy

Has everybody already been hitting C4 Past papers?

I must be late because I'm only starting them today and plan on getting x1 past paper done each day
leading until my mock next week. My class has just barely finished learning the content for core 4.
Is anybody else in the same boat?

Btw, when did TSR update the theme colour & post options.

How come? Copyright or something??


Posted from TSR Mobile

Probably, he just said Edexcel don't want them to be available to students online basically.

Thats abit stupid. Why do they make them then?


Posted from TSR Mobile

For the centres to use probably, maybe they want schools to use them as mocks or things, but its still a bit dumb.