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    Given that 5 sinxcosy + 4cosxsiny=0 and that cotx=2 find the value of coty

    really confused about even how to start this, many thanks
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    cosx/sinx = cotx....that's the only real hint I can give....It wants you to get it in that that form and use that value.
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    Right, think I've got it.

    Try and combine the sines and cosines into tans. Then you can rearrange to get "tan x = ?".

    Any idea where to go from there?
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    Right so I've divided by sin x to give

    5cosy/sinx +8siny/sinx = 0

    but now what?

    x everything by sinx?
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    cosx/sinx = cotx......cosxsiny/sinx = cotx.siny = 2siny....I think that's how they want you to approach it.
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    (Original post by joestevens2092)
    Right so I've divided by sin x to give

    5cosy/sinx +8siny/sinx = 0

    but now what?

    x everything by sinx?
    Multiplying everything by sin x will just get you back to where you started, won't it? :confused:

    This is how I approached it:

    5 sin x cos y + 4 cos x sin y = 0

    5 sin x cos y = -4 cos x sin y

    5 (sin x/cos x) = -4 (sin y/cos y)

    As someone else said, sin/cos = tan, and 1/tan (or cos/sin) = cot.
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    (Original post by Tortious)
    Right, think I've got it.

    Try and combine the sines and cosines into tans. Then you can rearrange to get "tan x = ?".

    Any idea where to go from there?
    Could I please send you my PS? :puppyeyes:

    My tutor claims that it shows no enthusiasm for Law... I disagree with him though. :rant:
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    We don't need tan, all we need is cot, which is 1/tan.....don't forget that!
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    (Original post by Doughnuts!!)
    Could I please send you my PS? :puppyeyes:

    My tutor claims that it shows no enthusiasm for Law... I disagree with him though. :rant:
    Are you stalking me, or did you just search my post history? :rofl:

    Of course you can. Is it "short enough" to PM me, or would you prefer my email address?

    /threadjacking
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    PS Helper
    (Original post by Tortious)
    Are you stalking me, or did you just search my post history? :rofl:

    Of course you can. Is it "short enough" to PM me, or would you prefer my email address?

    /threadjacking
    :rofl:

    I frequent the Maths forums quite a bit! When I saw your post on here I decided to ask cos my tutor trashed it. :bawling:

    HONESTLY! Oh, and it would be better to email it to you tbh!
 
 
 
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