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    Express 2cosx + 5sinx in the form Rcos(x - alpha), where R>0 and 0 < alpha < 90. Give the values of R and alpha to 3 significant figures. I get:
    5.39cos(x - 68.2) anyone else get this?
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    (Original post by imasillynarb)
    Express 2cosx + 5sinx in the form Rcos(x - alpha), where R>0 and 0 < alpha < 90. Give the values of R and alpha to 3 significant figures. I get:
    5.39cos(x - 68.2) anyone else get this?
    so 2cosx +5sinx = Rcosxcos(alpha)+Rsinxsin(alpha)
    therefore R^2=2^2 + 5^2,so R=sqrt(29)
    tan(alpha)=5/2 therefore alpha=68.199
    so 2 cosx +5sinx=sqrt(29)[cos(x-68.2)]
    best way to c if u've got it right is to leave alpha as arctan(5/2),take the cosine of that and multioly by sqrt29,if it = 2 then it is correct(and do the same for sine).
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    Is that really P2? We didnt do that until P5!
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    (Original post by fred0202)
    Is that really P2? We didnt do that until P5!
    You lucky f***. Trig was a horrible part of Edexcel P2, lucky the questions on the exam where nice though.
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    (Original post by fred0202)
    Is that really P2? We didnt do that until P5!
    p5............................ye a nice joke,in our p5(edexcel) we do some tough integration and coordinate geometry
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    (Original post by IntegralAnomaly)
    p5............................ye a nice joke,in our p5(edexcel) we do some tough integration and coordinate geometry
    I am not joking we didn't do that until P5, seriously.
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    (Original post by fred0202)
    I am not joking we didn't do that until P5, seriously.
    hahahaah yea that was funny, nice joke
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    (Original post by IntegralAnomaly)
    hahahaah yea that was funny, nice joke
    Look at the first question.

    http://www.aqa.org.uk/qual/gceasa/qp...W-QP-Jan03.pdf
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    (Original post by IntegralAnomaly)
    hahahaah yea that was funny, nice joke
    Err.. Why would he lie about that. You would have to be pretty sad.
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    (Original post by fred0202)
    Look at the first question.

    http://www.aqa.org.uk/qual/gceasa/qp...W-QP-Jan03.pdf
    bloody hell.... what did you have on P6?
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    (Original post by capslock)
    Err.. Why would he lie about that. You would have to be pretty sad.
    dunno why dont u ask him innit
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    Are you having a bloody jest??? P5, jesus
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    (Original post by elpaw)
    bloody hell.... what did you have on P6?
    P6 is further maths.
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    Err, almost all of the questions in that paper are covered by edexcel P2/P3.
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    God Bless the AQA board!!
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    (Original post by fred0202)
    P6 is further maths.
    so what's P5?
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    (Original post by fred0202)
    Look at the first question.

    http://www.aqa.org.uk/qual/gceasa/qp...W-QP-Jan03.pdf
    wooooooooottttttttt!!!!!!!! thats p3 stuff on edexcel!
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    (Original post by elpaw)
    so what's P5?
    Just the normal maths.

    For AQA you do P1, P2, (a choice between either M1 or S1), P4, P5 and (a choice between either M2 or S4), for a maths a-levels.
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    (Original post by fred0202)
    Just the normal maths.

    For AQA you do P1, P2, (a choice between either M1 or S1), P4, P5 and (a choice between either M2 or S4), for a maths a-levels.
    aaahhh, that's where the confusion comes from. in edexcel its P1-3 + 3of(M1-3,S1-3). anything with 4,5, or 6 is further,
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    Where did P3 go on AQA?
 
 
 
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