Resposta :
cos 225 / sen 225 = ...
225 - 180 = 45
cos 225 = - cos 45
cos 225 = -\/2/2
sen 225 = -\/2/2
tg 225 = 1
sec 45 = 1/cos 45 = 1/(\/2/2) = 2/\/2 = 2\/2/2 = \/2
cosec 30 = 1/sen 30 = 1/(1/2) = 2
calcule :
cotg 225 º ,sec 45 º ,cosec 30 º :
cos 225 / sen 225 = ...
225 - 180 = 45
cos 225 = - cos 45
cos 225 = -\/2/2
sen 225 = -\/2/2
tg 225 = 1
sec 45 = 1/cos 45 = 1/(\/2/2) = 2/\/2 = 2\/2/2 = \/2
cosec 30 = 1/sen 30 = 1/(1/2) = 2