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Reply 1900
Original post by chaosdestro0
Lies on the same line.

Thanks :smile:

Original post by otrivine
literally what you had to do was you have to find the 3 values from AP = OP-OA and the other point from PB and find the 3 points and once you did that you find the differences like for example (2,3,4) ( 4,6,8) you can see that it times by x2 and you have to do the similar thing to that question then you can easily get the ratio
sorry if my wording is bad


Lol thank you :biggrin: I get it now
Original post by jahani08
if anyone has done the jan 2012 paper question 5b, i don't understand how you get t to equal 0, pi/2, pi and 3pi/2. please help! :smile:


you get cos2t = 0 right>
you have to now let 2t = theta
get all the value for which cos theta = 0 so draw the graph out (cos graph)
then divide all the solutions by 2 to get T Then sub these values back into get the coordinates for x and Y

I hope im answering the right question, did the paper yesterday so kind of know what your on about!
Reply 1902
Original post by Jack_Smith
you get cos2t = 0 right>
you have to now let 2t = theta
get all the value for which cos theta = 0 so draw the graph out (cos graph)
then divide all the solutions by 2 to get T Then sub these values back into get the coordinates for x and Y

I hope im answering the right question, did the paper yesterday so kind of know what your on about!


thanks! do you find the other two solutions by using sin2t=0 as well (so you can get all 4 values of t)?

and good luck for tomorrow :smile:
Original post by browb003
Use the last of these trig identities to rewrite it as something that is integratable

img9.gif

2sin3x sin2x dx=cos5x+cosx dx \int 2sin3x \ sin2x \ dx = \int -cos5x + cosx \ dx

Are we given this identity? never seen it before !
Anybody else have a HUGE hatred for rates of change...
Reply 1905
Original post by otrivine
hello grazie how are u :wink: can i ask the question on finding position vectors do we need to find the variable like t and then sub into the equation vector?


Yeah, once you've got t (or lambda, mu, whatever), for a given position on a line then you can easily get the position vector from the line equation. However, it doesn't normally work like that. Normally you get t after you're given a position vector. Then you can use that t for other questions that may follow.
Reply 1906
Original post by Gibberish
Anybody else have a HUGE hatred for rates of change...

No, I luv em! Which means there won't be any on tomorrow's paper :wink:
Original post by grazie
Yeah, once you've got t (or lambda, mu, whatever), for a given position on a line then you can easily get the position vector from the line equation. However, it doesn't normally work like that. Normally you get t after you're given a position vector. Then you can use that t for other questions that may follow.


thanks and one thing mate hm the question http://www.edexcel.com/migrationdocuments/QP%20GCE%20Curriculum%202000/june2010-qp/6666_01_que_20100618.pdf
question 6)c) my answer was really close i got -1.21 and they got -1.13 ? hmm can i show you my working ? so you can tell me where i went wrong please :smile: shall i scan it if you want how should i scan it will take long?
Reply 1908
im really scared :frown:
Original post by awaydayboy
Are we given this identity? never seen it before !


Yeah it's on the C3 page of the formula booklet

http://www.edexcel.com/migrationdocuments/GCE%20New%20GCE/N38210A-GCE-Mathematical-Formulae-Statistical-Tables.pdf
(edited 11 years ago)
Original post by jahani08
thanks! do you find the other two solutions by using sin2t=0 as well (so you can get all 4 values of t)?

and good luck for tomorrow :smile:


but when you right the whole thing as a fraction doesnt the sin2t gets cancelled out when you multiply by 0. Hence why you have cos2t left!

Yep Good luck to you aswell! Can only speak about it 24 hours later :/ Sucks!!
Reply 1911
Original post by grazie
You either already know or can easily work out lambda for each of the points. Lambda is -6, -4, -1 for A, P, B resp. The ratios in lambda are the same as the ratios of segment lengths. So the ratio asked for is 2:3


oooooooo.. thankkss dudeee!
Man, I'm gonna need some divine intervention tomorrow.
Reply 1913
Original post by otrivine
thanks and one thing mate hm the question http://www.edexcel.com/migrationdocuments/QP%20GCE%20Curriculum%202000/june2010-qp/6666_01_que_20100618.pdf
question 6)c) my answer was really close i got -1.21 and they got -1.13 ? hmm can i show you my working ? so you can tell me where i went wrong please :smile: shall i scan it if you want how should i scan it will take long?


Yeah, I'll look it over, but I can't tell you how to get it uploaded.
can anyone please help me with a vector question in the text book? page84 question 12 d... please please please....
Original post by geditor
im really scared :frown:


I feel like im prepared after doing the solomon, elmwood and edexcel but then i feel like im not and im going to open that paper tomorrow and my mind is going to be blank :/

So dont worry im with you on being scared for this!
Original post by bunnyhana
can anyone please help me with a vector question in the text book? page84 question 12 d... please please please....


i think you dot product the equation of line l with the scalar quantity of line l which equals to 0. You then find lamda which you would sub back into the equation of l to get the position vector of c!

I think my wording is very crappy, if you dont get it let me know i would try and show the working out!
Reply 1917
anyone have any clue about similar triangless ?? =\
Original post by grazie
Yeah, I'll look it over, but I can't tell you how to get it uploaded.


ok i used the integration by parts , and this was my final answer for integration

(1/2+7/2cos2x) (x) + (7/2) (1/2-1/2cos2x)+c
Reply 1919
how would you intergrate, 2/(1+x)^2 dx?

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