Question

упростите ctg(-t)*sin(-t) cos(t+ 3П)

Answer 1

-ctgt*(-sint)cos(П+t)=cost*(-cost)=-cos^2t

Answer 2

 $ctg(-t)cdot sin(-t)cdot cos(t+3pi )=(-ctgt)cdot (-sint)cdot cos(pi +t)=\\=frac{cost}{sint}cdot sintcdot (-cost)=-cos^2t$