Question

2 корень 3 cos^2 13п/12 - корень из 3

Answer 1

$2 sqrt{3}cos^{2}frac{13 pi }{12}- sqrt{3}\sqrt{3}(2cos^{2}frac{13 pi }{12}-1)= sqrt{3}(cos2*frac{13 pi }{12})\ sqrt{3}(cos(2pi+frac{pi }{6}))= sqrt{3}* frac{ sqrt{3}}{2} =1,5$