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Edexcel A2 C4 Mathematics June 2016 - Official Thread

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In C3, will we be questioned on the Factor Formulae ? It's not actually mentioned on the Edexcel C3 specification. Will this also mean that we won't get asked to integrate 2sin3xcos2x in C4 ?
Original post by Danllo
In C3, will we be questioned on the Factor Formulae ? It's not actually mentioned on the Edexcel C3 specification. Will this also mean that we won't get asked to integrate 2sin3xcos2x in C4 ?


I don't think its on the spec (someone correct me if I'm wrong) and from every single past paper I've done I've not encountered it once.
Original post by Danllo
In C3, will we be questioned on the Factor Formulae ? It's not actually mentioned on the Edexcel C3 specification. Will this also mean that we won't get asked to integrate 2sin3xcos2x in C4 ?


Original post by XxKingSniprxX
I don't think its on the spec (someone correct me if I'm wrong) and from every single past paper I've done I've not encountered it once.


It's not on the specification.
Original post by Craig1998
Are you struggling to integrate ?


Idk where to start actually. Could you tell me the steps please?
Original post by sabahshahed294
Idk where to start actually. Could you tell me the steps please?


Try starting by multiplying through by dt.

As a note, what they ask in part a will usually guide you later in chunkier questions like this.
Attachment not found
image.png Hey guys can someone explain the limits used on the integration to find the area ?
Original post by Craig1998
Try starting by multiplying through by dt.

As a note, what they ask in part a will usually guide you later in chunkier questions like this.


Um, okay. Thanks! :smile:
Original post by lfcrules
Attachment not found
image.png Hey guys can someone explain the limits used on the integration to find the area ?


Anyone know why? I'm kinda confused as well... @13 1 20 8 42
(edited 7 years ago)
Original post by Don Pedro K.
Anyone know why? I'm kinda confused as well... @13 1 20 8 42


I seem to remember this question frustrating me a lot when prepping for C4, but looking at it now, just seems you're integrating between the two values of t for which x = 5/2, which is kind of intuitive no? Important to note that in this region the integral is positive and you will be getting the "positive area" so to speak
Original post by 1 8 13 20 42
I seem to remember this question frustrating me a lot when prepping for C4, but looking at it now, just seems you're integrating between the two values of t for which x = 5/2, which is kind of intuitive no? Important to note that in this region the integral is positive and you will be getting the "positive area" so to speak


Could you maybe draw a diagram to show which bits we're finding? Because I thought that we had to find this area:

image.jpg
Original post by Don Pedro K.
Could you maybe draw a diagram to show which bits we're finding? Because I thought that we had to find this area:

image.jpg


That is correct. I think I remember where my confusion lied, it was in justifying that the integrand from integrating y with respect to x between these two t points is actually the area. I think this justification is a bit complicated and the question expects you to just assume that the way they have done it, the simple way of just saying "oh we'll integrate ydx and translate to t", will work. I am pretty sure a question like this will not come up.
Original post by 1 8 13 20 42
That is correct. I think I remember where my confusion lied, it was in justifying that the integrand from integrating y with respect to x between these two t points is actually the area. I think this justification is a bit complicated and the question expects you to just assume that the way they have done it, the simple way of just saying "oh we'll integrate ydx and translate to t", will work. I am pretty sure a question like this will not come up.


But if that is the area that we need to find, surely that would be between the points x = 2 and x = 2.5 so when you sub that in for x = t + 1/t, you get t = 1 and t = 2 not t = 1/2 and t = 2 :s?
Original post by Don Pedro K.
But if that is the area that we need to find, surely that would be between the points x = 2 and x = 2.5 so when you sub that in for x = t + 1/t, you get t = 1 and t = 2 not t = 1/2 and t = 2 :s?


But as you showed earlier in the question x = 2.5 has two t-solutions
Original post by Don Pedro K.
But if that is the area that we need to find, surely that would be between the points x = 2 and x = 2.5 so when you sub that in for x = t + 1/t, you get t = 1 and t = 2 not t = 1/2 and t = 2 :s?


integrate between 5/2 and 2 is what I would do, definitely looks like that to me
Have you got an answer for the question?
Original post by k.russell
integrate between 5/2 and 2 is what I would do, definitely looks like that to me
Have you got an answer for the question?


This is what I thaught as well , but then would you get the area above the x axis or below ?
Original post by sabahshahed294
Idk where to start actually. Could you tell me the steps please?


Turn it into partial fractions before integrating
Just want someone to confirm since I remember something faintly from integration by volume of revolutions.

If you integrating the volume of revolutions by the x axis you do: pi . integral (y)^2 dy/dx
BUT if you integrate the volume of revolutions by the y axis you do: pi . integral (x)^2 dy/dx

Correct? :erm:
Q) Those that are sitting their AS level maths is their exams still under the current spec so when they go into
A2, would they still have a chance to resit some of their exams next year? I thought the exam board (Edexcel)
will have its A level Maths curriculum changed in 2017 .*. meaning anybody sitting maths exams from 2017
would be sitting different spec papers .*. would the current AS level maths students under the spec atm be
affected next year if they would resit?

:confused: *flashback* @Michael gove :mob:
(edited 7 years ago)

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