Question

найдите значение выражения

Answer 1

$sqrt{2} (1 - 2( sin(2pi - frac{pi}{8} ) )^{2} = \ = sqrt{2} (1 - 2( - sin( frac{pi}{8} ) ) ^{2}) = \ = sqrt{2} (1 - 2( sin( frac{pi}{8} ) ) ^{2} ) = \ = sqrt{2} cos(2 times frac{pi}{8} ) = sqrt{2 } cos( frac{pi}{4} ) = \ = sqrt{2} times frac{ sqrt{2} }{2} = 1$

Answer 2

спасибо большое