Respuesta :
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
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