Упростите: ctgt*sin(-t)+cos(2pi-t)

Question

Упростите: ctgt*sin(-t)+cos(2pi-t)

Answer 1

Ctgt=cost/sint
sin(-t)=-sint
cos(2π-t)=cost

ctgt*sin(-t) + cos(2π-t)=cost*(-sint)/sint + cost=-cost+cost=0