4sin(-7π÷4)cos(-4π÷3)ctg3π÷4

4sin(-7π/4)cos(-4π/3)ctg3π/4=-4sin7π/4 cos4π/3ctg4π/3=-4sin(2π-π/4)cos(π+π/3)ctg(π-π/4)=4sinπ/4(-cosπ/3)(-ctgπ/4)=4*√2/2*1/2*1=√2