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I got a maths problem and just checking whether my answer and method is correct:

Tan(A+B/2) / Tan (A-B/2) = SinA + SinB / SinA - SinB 

I started to solve it:

Tan(A+B/2) = Sin(A+B)/2Cos   Tan(A-B/2) = Sin(A-B)/2Cos   

2Cos'es cancel out each other and leaves

Sin(A+B)/Sin(A-B) SinA + SinB / SinA - SinB 

Is my method correct? Just checking whether Tan(A+B/2) = Sin(A+B)/2Cos

~Thanks.

  • 0
    Do you mean $\tan\left(\frac{A+B}{2}\right)$?2012-12-31
  • 3
    $\dfrac{\sin(A+B)}{2\cos}$ is complete gibberish.2012-12-31
  • 0
    @ChrisEagle: And even if it wasn't complete gibberish, it wouldn't be equal to $\sin \left( \dfrac{A+B}{2\cos} \right)$.2012-12-31
  • 1
    Yes, the gibberish nature makes it hard to figure out what the author intended. My guess is that the argument of $\cos$ has been left out. It also seems the author thinks that $\sin$ is a linear function.2012-12-31
  • 0
    The [tag:complex-multiplication] tag does not mean what you think it does. Please read the [tag description](http://math.stackexchange.com/tags/complex-multiplication/info) before adding it again.2013-01-15

3 Answers 3