Jawabanmu

2014-05-20T15:00:46+07:00
(cosx+sinx) =
(cosx-sinx)


(cosx + sinx)(cosx + sinx) / (cosx - sinx)(cosx + sinx)
= cos²x + 2sinx cosx + sin²x / cos²x - sin²x
= 1 - sin²x + 2sinx cosx + sin²x / 1 - sin²x - sin²x
= 1 + 2sinx cosx / 1 - 2sin²x
= 1 + sin2x / 1 - 2sin²x