Question

cos^2 (- пи/12) решите пожайлуста

Answer 1

$cos^2\frac{\pi}{12} =\frac{1+cos\frac{2\pi}{12}}{2} =\frac{1+cos\frac{\pi}{6}}{2} =\frac{1+\frac{\sqrt{3}}{2}}{2}=\frac{\frac{2+\sqrt{3}}{2}}{2} =\frac{2+\sqrt{3}}{4}$