Question

15 и 17 только спасибо)

Answer 1

$sqrt{2}sinfrac{pi}{8}*cosfrac{pi}{8}=frac{sqrt{2}}{2}(2sinfrac{pi}{8}cosfrac{pi}{8})=frac{sqrt{2}}{2}*sin(2*frac{pi}{8})=frac{sqrt{2}}{2}*sinfrac{pi}{4}=\=frac{sqrt{2}}{2}*frac{sqrt{2}}{2}=frac{1}{2}$


$sqrt{75}-sqrt{300}sin^2frac{13pi}{12}=sqrt{75}(1-2sin^2frac{13pi}{12})=sqrt{75}*cos(2*frac{13pi}{12})=\=sqrt{75}*cosfrac{13pi}{6}=sqrt{75}*cosfrac{pi}{6}=sqrt{75}*frac{sqrt{3}}{2}=frac{15}{2}$

Answer 2

описался. исправил.