2. Resolución de las identidades 11 y 13
11) 1 = tang x 13) 1 = cotg x
cos x . Cosec x sen x . sec x
1 = tang x 1 = cotg x
cos x . 1 sen x . 1
sen x cos x
1 = tang x 1 = cotg x
cos x sen x
sen x cos x
sen x = sen x cos x = cos x
cos x cos x sen x sen x