Question

sabendo que cose x=13/5 e π/2 c x c π,calcule:
a)sem x=
b)cos x=
c)tg x =
d)cotg x =
e)sec x =

Answer 1

π/2 < x < π

sen² x + cos² x = 1
sen² x = 1 - cos² x
sen² x = 1 - (13/5)²
sen² x = - 169/25
sen x = √-144/√25
sen x = 12i/5

cos x = - 13/5

tg x = sen x/cos x
tg x = 12i/5/13/5
tg x = - 12i/13

cotg x = 1/tg x
cotg x = - 1/12i/5
cotg x = - 1/60i

sec x = 1/cos x
sec x = - 1/13/5
sec x = - 1/65