Respostas

2013-10-14T23:51:40-03:00
A) cotg 150º = 1/tg 150 = 1/ (sen 150/ cos 150) = 1 . (cos 150/ cos 150) = - cos 30/ sen 30 = - raiz 3/2  /  1/2 = -raiz3

1 5 1
b)sec π = 1/cos (π/3) = 1/ cos 60 = 1/ (1/2) = 2
3
obrigada :)