Question

помогите, пожалуйста

Answer 1

$star ; cos(13,5pi +6)=cos(14pi -frac{pi}{2}+6)=cos(-frac{pi }{2}+6)=cos(frac{pi}{2}-6)=sin6\\star ; ctg(17,5pi -3)=ctg(18pi -frac{pi}{2}-3)=ctg(-frac{pi}{2}-3)=ctg(-(frac{pi }{2}+3))=\\=-ctg(frac{pi}{2}+3)=-(-tg3)=tg3\\star ; sqrt{9-6pi +pi ^2}=sqrt{pi ^2-6pi +9}=sqrt{(pi -3)^2}=|underbrace {pi -3}_{>0}|=pi -3\\star ; sin(pi -3)=sin3\\star ; cos(pi -3)=-cos3\\star ; sin3cdot cos3=frac{1}{2}sin6\\\frac{cos(13,5pi +6)cdot ctg(17,5pi -3)}{sin(sqrt{9-6pi +pi ^2})cdot cos(sqrt{pi ^2-6pi +9})}=frac{sin6cdot frac{sin3}{cos3}}{sin(pi -3)cdot cos(pi -3)}=frac{2cdot sin3cdot cos3cdot tg3}{-sin3cdot cos3}=-2cdot tg3$