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    2cot^2 \theta = 7 cosec \theta - 8

    Help please! :p:
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    (Original post by Narik)
    2cot^2 \theta = 7 cosec \theta - 8

    Help please! :p:
    use cot^2=cosec^2x-1
    and solve the quadratic
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    (Original post by rbnphlp)
    use cot^2=cosec^2x-1
    and solve the quadratic
    Is that in C3? :confused:
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    \cot^2(\theta)+1=\csc^2(\theta)

    Substituting this in:

    2 \{ \csc^2 ( \theta ) - 1 \} =7 \csc( \theta )-8

    When you simplify this now, you'll get a quadratic.
    And then if you can work out  \csc ( \theta ), you can find \sin(\theta) and then \theta itself hopefully!
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    (Original post by Narik)
    Is that in C3? :confused:
    Probably.
    Annoying as it is, it depends which specification you do :woo:
    So which one eez eet? :teeth:
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    (Original post by Narik)
    Is that in C3? :confused:
    it is ..you should be familiar with identites to solve problems like this,
    cot^2x+1=cosec^2x
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    Oh yeah! Of course it is. I totally forgot about that identity. Thanks guys! :facepalm:
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    (Original post by Narik)
    Oh yeah! Of course it is. I totally forgot about that identity. Thanks guys! :facepalm:
    No problem; out of interest, how many solutions were there in the end?
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    (Original post by placenta medicae talpae)
    No problem; out of interest, how many solutions were there in the end?
    There were 4:
    45*, 116.7*, 225* and 296.6*

    Thanks for the help.
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    (Original post by Narik)
    There were 4:
    45*, 116.7*, 225* and 296.6*

    Thanks for the help.
    Ooh, interesting! :woo:
    Hmm, I think there's a way to do degree-symbols.
    I'll investigate :teeth:

    No problem
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    Ooh - it's ^\circ in LaTeX:

    225^ \circ
 
 
 
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