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Homework Help: Need a hint

  1. Jul 4, 2008 #1
    1. The problem statement, all variables and given/known data

    sin x+cos x + tan x + cosec x + sec x+tan x +cot x = 8

    find sin2x=?

    i still have no idea to deal with this problem, hint please
  2. jcsd
  3. Jul 4, 2008 #2


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    Look up the identities for rewriting cos tan etc in terms of sin.
  4. Jul 4, 2008 #3


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    Write out each term that isn't sin x or cos x in terms of its definition as a ratio of sine and/or cosine. (Does tan x really appear twice? How many terms are there supposed to be? Is this copied correctly? I ask so we don't waste time trying to solve the wrong problem... Are you sure this isn't

    [sin x·cos x] + tan x + cosec x + [sec x·tan x] + cot x , for instance?)

    You will now have a set of terms that you can add as fractions by putting everything over a common denominator. You will be able to make some simplifications in the numerator using trig identities. You should end up with something easier to work with. (But make sure this is copied right, or a solution will be truly hopeless...)
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