Задача 23457 32/sin(-35П/4)cos25П/4...

u10925276140

07.02.2018

32/sin(-35П/4)cos25П/4

SOVA

07.02.2018

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cos(25Pi/4)=cos((24Pi/4)+(Pi/4))=cos(6Pi+(Pi/4))=cos(Pi/4)

sin(-35Pi/4)=sin((-32Pi/4)-(3Pi/4))=
=sin(-8Pi-(3Pi/4))=sin(-3Pi/4)= - sin(Pi/4)

sin(–35Pi/4)cos(25Pi/4)=-sin( Pi/4)*cos(Pi/4)=-(1/2)*(2*sin( Pi/4)*cos(Pi/4))=-(1/2)*sin(Pi/2)=-1/2

О т в е т. 32/(-1/2)=-64