Respuesta :

Answer:

[tex]\frac{1}{\sqrt{2}}[/tex]

Step-by-step explanation:

cos(-315)° = cos 315°

  • The cosine function is an even function.

cos 315° = cos 45°

  • cos(360°-x)=cos(x)

This is equal to

[tex]\frac{1}{\sqrt{2}}[/tex]