Корень из 300 cos квадрат х 13П/12-корень из 75

[latex]sqrt{300}cos^2frac{13pi}{12}-sqrt{75}=sqrt{75}(sqrt{4}*cos^2frac{13pi}{12}-1)=sqrt{75}(2*cos^2frac{13pi}{12}-1)\=sqrt{75}*cos(2*frac{13pi}{12})=sqrt{75}*cosfrac{13pi}6=sqrt{75}*cos(frac{13pi}6-2pi)=\=sqrt{75}*cos(frac{13pi}6-frac{12pi}6)=sqrt{75}*cosfrac{pi}6=sqrt{75}*frac{sqrt3}2=frac{sqrt{225}}2=frac{15}2=7,5[/latex]