IDENTIDADES TRIGONOMETRICAS. AYUDENME PORFAVOR a) (cos x - sen x)^2 + 2 sen x .cos x = 1 b) 1-2 sen^2 x = 2 cos^2 x - 1 c) (1/1+ sen x)+ (1/1- sen x) = 2 sec^2 x d) sen^4 x - cos^4 x = 2 sen^2 x-1 e) ( 1/ sen x . cos x) - ctg x = tg x f) (tgx/ sen x) + ( csec x /tg x) = csec^2 x . sec x g) (secx/senx) - tg x = ctg x h) ( 1 +cos x/ senx)+ ( sen x / 1+ cos x) = 2 csec x