Question

Ayúdenme::

Reducir:

           Sen(X+Y) + Sen(X-Y)

P=     -----------------------------

             CosX x CosY

Answer 1

        SenXCosY+SenYCosX+SenXCosY-CosXSenY

       --------------------------- -------------------------

                     CosXxCosY

             2SenXxCosY

         -----------------------=2Tan

               CosXxCosY

Answer 2

Sen(x+y) + Sen(x-y)
--------------------------------=
Cosx * Cosy

senx*cosy+seny*cosx+senx*cos(-y)+sen(-y)*cosx
----------------------------------------------------------------------=
Cosx * Cosy

senx*cosy+seny*cosx+senx*cosy-seny*cosx
----------------------------------------------------------------------=
Cosx * Cosy

senx*cosy+senx*cosy
-------------------------------=
Cosx * Cosy

2senx*cosy
-----------------=
Cosx * Cosy

2senx
----------=2tanx
Cosx 

por lo tanto:

Sen(x+y) + Sen(x-y)
--------------------------------=2tanx
Cosx * Cosy