Question

Se cossec x= 3V5/5 , determine o cos x.​

Answer 1

Se cossec x= 3V5/5 => senx = 5/3√5

cosx = √1 -sen²x

cosx = √1 -(5/3√5)²

cosx = √1 -(25/45)

cosx = √9/9 -(5/9)

cosx = √4/9

cos x = ± 2/3

Answer 2

Resposta:

Explicação passo-a-passo:

cossec x= 3V5/5 , determine o cos x.​

Cossec x = 3√5/5

Cossec x = 1/sen x

3√5/5 = 1/sen x

sen x . 3√5 = 5

Sen x = 5/3√5 . √5/√5

Sen x = 5.√5/3√5.√5

Sen x = 5√5/3.5

Sen x = √5/3

Sen^2 x + cos^2 x = 1

(√5/3)^2 + cos^2 x = 1

5/9 + cos^2 x = 1

Cos^ 2 x = 1 - 5/9

Cos^2 x = (9-5)/9

Cos^2 x = 4/9

Cos x = √(4/9)

Cos x = 2/3

Resp.:

Cos x = +/- 2/3