Question

$log_{ \frac{1}{ \sqrt{2} } }(cos {}^{2} 22.5° - sin {}^{2} 22.5°) =$
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Answer 1

$log_\frac{1}{\sqrt{2} }(cos^222.5-sin^222.5)= log_\frac{1}{\sqrt{2} }(cos45)=log_\frac{1}{\sqrt{2} }(\frac{1}{\sqrt{2} })=1$

Answer 2

Ответ:

log_1/√2*(cos²22,5°-sin²22,5°)=log_1/√2cos(2*22,5°)=log_1/√2cos45°=log_1/√2 1/√2=1.