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1. 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
2. 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)
3. 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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