Question

Срочно нужны решение ​

Answer 1

Ответ:

$\cos {}^{2} ( \frac{\pi}{4} ) - \sin {}^{2} ( \frac{\pi}{4} ) = ( \frac{ \sqrt{2} }{2} ) {}^{2} - ( \frac{ \sqrt{2} }{2} ) {}^{2} = 0$