Question

Se senx = 3/4 e seny = 2/5, calcule o valor de sen(x - y).

Answer 1

Resposta:

tg + cot = 2

sen/cos + cos/sen = 2

(sen²x+cos²x)/(sen x*cos x) = 2

1/(sen x*cos x) = 2

y = sen x * cos x

y = 1/2