Respuesta :

ghanami
hello : 
sinθ = 15/17
 use pythagorean identity : cos²θ +sin² θ = 1 
cos²θ =  1 - sin² θ
cos²θ = 1-(15/17)² 
cos²θ = 1- 225/289
cos²θ = 64/289
cos²θ = (8/17)²
cosθ = 8/17 or -8/17

Answer:

Cosine (theta) = plus or minus 8/17