The expression \(1 - 2\sin^2(22.5°)\) is equal to:
Answer: C
This is in the form of the cosine double angle identity: \(\cos(2A) = 1 - 2\sin^2 A\).
Here, A = 22.5°.
The expression is equal to \(\cos(2 \times 22.5°) = \cos(45°)\).
The value of \(\cos 45°\) is \(1/\sqrt{2}\).