3)cos(-π)+ctg(-π/2)-sin(-3/2π)+ctg(-π/4)=
4)3-sin^2(-π/3)-cos^2(-π/3)/2cos(-π/4)=

3)cos(-π)+ctg(-π/2)-sin(-3/2π)+ctg(-π/4)=   -1+0 -1 -1=-3

4)3-sin^2(-π/3)-cos^2(-π/3)/2cos(-π/4)=3 -3/4-1/4/1=2