Question

вычислить 1-sin^2 22.5°​

Answer 1

sin^2 (t/2) = (1 - cos t) / 2

1 - sin^2 22,5° = 1 - (1 - cos 45°) / 2 = 1 - (1 - √2/2) / 2 = 1 - (2 - √2)/4 =

= (2+√2)/4 = 1/2 + (1/4)√2