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trig C3 help please watch

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    hey

    just attempted a question, i got so far then went a bit downhill

    my answer to this q is 2sin45cos30/-2sin45sin(-30)
    which is what is in the bak of my book in the answers however
    it goes on to say that the expression equals 1/tan30
    could any please explain as i cant see how they got the numerator to =1
    ot the denomonator to = tan30

    thanks
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    Well remember that sin(-30) = -sin(30)

    You can cancel 2sin45 from the top and bottom, which would leave you with cos(30)/sin(30)

    Then remember sin(x)/cos(x) = tan(x)

    So cos(30)/sin(30) = 1/tan(30)
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    ah yes, i was doin the cos(-30) instead which totally screws it up, such a stupid mistake thanks so much for ur help!
 
 
 
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Updated: January 28, 2009

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