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    (Original post by sunsri101)
    But it said 'Using De Moivre's Theorem'. Technically, z^n -z^-n = 2i sin theta is not De Moivre's Theorem, it's an application of it.
    If you're using an application of De Moivre's theorem you are implicitly using De Moivre's theorem.

    They said "use". Surely then It stands to reason that I can use it packaged in an application?
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    (Original post by taichingkan)
    Yeah true, hopefully they give us full credit :/
    You'll get full credit if your coefficients are correct and you've shown the application of de Moivre's theorem for sure.
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    (Original post by Euclidean)
    You'll get full credit if your coefficients are correct and you've shown the application of de Moivre's theorem for sure.
    Okay then, thanks!
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    (Original post by Euclidean)
    You'll get full credit if your coefficients are correct and you've shown the application of de Moivre's theorem for sure.
    How about for the first part of last q I wrote it as plus and minus 0.722 rather than arcosh0.75. It didn't say exact form I think so would it gain full marks?
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    (Original post by Rkai01)
    How about for the first part of last q I wrote it as plus and minus 0.722 rather than arcosh0.75. It didn't say exact form I think so would it gain full marks?
    Perfectly fine so long as you've shown how you got there

    You probably also needed to write P[21/4, 0.722] and Q[21/4, -0.722] though, defining them separately as P is above the initial line and Q below in their definition
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    how many marks was question 1?
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    (Original post by dragozox)
    how many marks was question 1?
    6 I believe
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    (Original post by Euclidean)
    Perfectly fine so long as you've shown how you got there

    You probably also needed to write P[21/4, 0.722] and Q[21/4, -0.722] though, defining them separately as P is above the initial line and Q below in their definition
    Oh yeah I did that I just mean the form of the angle was my issue, ty
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    thanks!!
    (Original post by somevirtualguy)
    6 I believe
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    For 8b, I used the right integration method for finding the area from the cardioid graph, however I got the area of the sector wrong. (I used the method for working out the sector of a circle using radians but stupidly used the value of r from 8a instead of the radius). Realistically, how many marks might I get?
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    For the differential equation, would it have been possible to integrate by substitution?? Taking e^(2 theta) as u?
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    For the z^4=8(root3+i) i used values of k=0,1,2 and 3. Is that wrong?
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    (Original post by AhnafR)
    For the z^4=8(root3+i) i used values of k=0,1,2 and 3. Is that wrong?
    No as the question didn't specify a range for the argument, thou using those values conveniently makes all the arguments between zero and 2pi.
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    Guys for the z^4 question i used limits of 0<x <2pi instead of -pi <x <pi but my argand diagram looks the same. Is it wrong and how many marks would I lose?
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    (Original post by Smeagul)
    No as the question didn't specify a range for the argument, thou using those values conveniently makes all the arguments between zero and 2pi.
    So the arguments between 0 and 2pi would be correct?
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    (Original post by Pixel_Green)
    Your answers may have different sf but they have the same dp. Although I doubt they'd penalise you for different sf, I usually tend to go to 4 or 5dp in my answers in pure just to be safe if the answer is not exact, so I work either exact up to that point or to 6dp, then write my answer to about 4dp.

    Depends what accuracy they want, though if you have a solid part (a) I think they'd give you 2 for (b) if your numbers were all accurate
    Hopefully they are lenient. My part a was solid. Last year I thought that I had lost quite a few marks in C2 (was feeling very unwell) but somehow I got 74/75 even though I knew I had made at least 9 marks worth of errors. On results plus it said they were correct even though they definitely weren't xD. Great marking but I'm not complaining.
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    should be fine as they did not mention any specific range
    (Original post by AhnafR)
    For the z^4=8(root3+i) i used values of k=0,1,2 and 3. Is that wrong?
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    (Original post by Rkai01)
    For the last question first part I wrote it as 0.722, -0.722 or something rather than plus/ minus arcosh(0.75). Would that still get marks cause it didn't say in exact form?
    Pretty sure it was 0.723 to 3dp
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    (Original post by AhnafR)
    For the z^4=8(root3+i) i used values of k=0,1,2 and 3. Is that wrong?
    as far as i remember k=3 would have been outside range -\pi < 0 < \pi. If they asked for a range (which i cant remember), then am afraid so. k=-2 would have been the one to use (please correct me if im wrong! - we were always taught to put it in that range anyways)
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    (Original post by target21859)
    Pretty sure it was 0.723 to 3dp
    Yes it was can't remember what I put but I'm assuming i lost a mark.
 
 
 
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