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Homework Help: Trig Identities that I can't get a grip on

  1. May 31, 2009 #1

    I tried to prove this trig identity but I an really stuck. I think tan of pi/4 is '1', and if I do that then my numerator becomes zero, thus zero=2sinxcosx. But that can't be right, so I don't know what to do now.

    LS= (1+tanx-1-tanx)/(1+tanx+1-tanx)

    I get 0=2sinxcosx

    Any thoughts? Also, I am wondering where this advanced formatting option is or how to do it.
  2. jcsd
  3. May 31, 2009 #2
    You will need to use the identities


  4. May 31, 2009 #3
    Thankyou Overt, I did not see it.

    So would I be right in assigning 'y' as pi/4? and let 'x' be 'x'?

    For tan(pi/4+x) I will instead get (tanx+tanpi/4)/(1-tanxtanpi/4)?
  5. May 31, 2009 #4
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