Answer:
[tex]\frac{1}{\sqrt{2} }[/tex]
Step-by-step explanation:
Cosine (cos) is adjacent by hypotenuse. [tex]\frac{adjacent}{hypotenuse}[/tex]
In any of the 45° angles, 1 is adjacent and √2 is the hypotenuse.
So arrange them to get [tex]\frac{1}{\sqrt{2} }[/tex]
