Question

Calcule o valor de :
a) sec PI / 6
b) cotg 2PI / 3
c) cossec 5 PI / 6
d) sec 210°
e) cossec 315°
f) cotg 45°

Answer 1

a) sec PI / 6

Sec pi / 6 = 1/cos pi/6 ( 30° = V3/2)

Sec 30 = V3/2

b) cotg 2PI / 3

Cotg 120° = cos 120° / sen 120°

Cotg 120° = -1/2 / V3/2 = -2/2V3 = -V3/3

c) cossec 5 PI / 6

Cossec 150° = 1/ 1/2

Cossec 150° = 2

d) sec 210°

Sec 210 = 1/cos 210

Sec 210 = 1/-V3/2

Sec 210 = -2V3/3

e) cossec 315°

Cossec 315 = 1/-V2/2

Cossec 315 = -2V2/2 = -V2

f) cotg 45°

Cotg = cos 45 / sen 45

Cotg = V2/2 / V2/2

Cotg = 1