Question

Sabendo que sec x = -5/4 e π < x < 3π/2 calcule:

a)cos x b)sen c)tag x d) cotg x e) cossec x

Answer 1

a) sec x = 1 /cos x
cos x = - ( - 4 /5 )
cos x. = 4 /5
b) sen (x) 2 + cos (x ) 2 = 1
sen (x ) 2 = 1 - cos (x ) 2
sen (x ) 2 = 1 - ( 4 / 5 ) 2
sen ( x ) 2 = 1 - 16 / 25
sen ( x ) 2 = 25 / 25 - 16 /25
sen ( x ) 2 = 9 / 25
sen x = √,9 /25
sen x = 3 / 5
sen x = - 3 / 5
c) tag x = sen x / cos x
tag x = - 3 / 5 ÷ 4 / 5
tag x = - 3/ 4
d) cotg = - 4 / 3
e) cossec x = 1 / sen x
cossec x = - 5 / 3