Respuestas

2013-04-18T11:56:16+02:00

sec = 1 / cos;   tan = sen / cos

 

[(1 / cos x) + (sen x / cos x) ] = 1 / [(1 / cos x - sen x / cos x)]

 

( 1 + sen x / cos x ) = 1 : (1 - sen x / cos x)

 

(1 + sen x / cos x) = (cos x / 1 - sen x)

 

(1 + sen x) (1 - sen x) = cos 2 x

 

1 - sen 2 x = cos 2 x

 

cos 2 x + sen 2 x = 1 (Ecuación fundamental de la trigonometría)