sin2π／3=?；cos2π／3=?；sin7π／6=?；cos7π／6=?说下

sin2π／3=?；cos2π／3=?；sin7π／6=?；cos7π／6=?说下

sin2π／3=sinπ／3=√3/2
cos2π／3=-cosπ／3=-1/2
sin7π／6=-sinπ／6=-1/2
cos7π／6=-cosπ／6=- √3/2

(根号3)/2
-1/2
-1/2
-(根号3)/2

sin2π／3=√3/2；cos2π／3=-1/2；sin7π／6=-1/2；cos7π／6=-√3/2