Question

корень из 2 sin 13п/8 cos 13п/8

Answer 1

$sqrt{2sin(frac{13pi}8)cos(frac{13pi}8)}=sqrt{sin(2*frac{13pi}8)}=sqrt{sin(frac{13pi}4)}=\\=sqrt{sin(frac{5pi}4)}=sqrt{-frac{sqrt2}2$