Answer:
[tex]\frac{\sqrt2}2 + 1[/tex]
Step-by-step explanation:
We can use the following identity to determine the value of this function.
[tex]\cos(2\alpha) = 2\cos^2(\alpha) - 1[/tex]
In our case, [tex]\alpha = 22.5[/tex]
[tex]2\cos^2(22.5)\\\to 2\cos^2(22.5) - 1 + 1\\\to \cos(2 \times 22.5) + 1\\\to \cos(45) + 1\\\to \frac{\sqrt2}2 + 1[/tex]
