Sin35sin84 + cos145sin6/ cos50sin21- cos40sin111=
(sin35*sin(90-84)+cos(180-35)sin6)/(cos(90-40)sin21-cos40sin(90+21))= =(sin35cos6-cos35sin6)/(sin40sin21-cos40cos21)=sin(35-6)/-cos(40+21)= =-sin29/cos61=-sin29/cos(90-29)=-sin29/sin29=-1