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Proving trignometric identities.

  1. Mar 21, 2013 #1
    1. The problem statement, all variables and given/known data
    I understand this chapter a little better than the previous ones, but I'm having problems with these two problems. Can anyone at least lead me in?

    2. Relevant equations

    3. The attempt at a solution
    Starting from the right side for both. For the second one, turning the 1 into cos2α+sin2α. cot2α+cos2α+sin2α? I'm not sure of if this a good start, because I'm stuck from this point on.

    Attached Files:

  2. jcsd
  3. Mar 21, 2013 #2


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    I personally find the use of tan, cot and csc quite confusing. I always prefer to just rewrite everything in terms of sin and cos and then the simplification sometimes becomes more obvious.
  4. Mar 21, 2013 #3

    As CompuChip suggested, rewrite the [itex]\tan[/itex] and [itex]\cot[/itex] as fractions of [itex]\sin[/itex] and [itex]\cos[/itex]. Then, make sure you have common denominators before adding or substracting.

  5. Mar 21, 2013 #4


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    Why do you want to work on the right side on either of these?

    Work on the left side using the excellent suggestions of the previous responders. It's fairly straight forward to get the left hand side to agree with the right hand side.

    ... then if you must work only on the right hand side, reverse the steps you used on the left side.
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