Respuesta :

caylus
Hello,

as cos 2x=cos²x-sin²x=1-2sin²x
then
cos 2x+sin x=-2sin² x+sin x +1
[tex]cos 2x+ sinx= cos^{2}x - sin^{2}x + sin x=
 =(cosx-sinx)(cosx+sinx)+sinx [/tex]
This is the expression written with only sinx and cosx.