(jω
c
)=-arctan2ω
c
-arctan0.1ω
c
=-84.29°=-26.57°=-110.86°

(jω
c
)=arctan0.1ω
c
-90°+(-π-arctanω
c
)。)=-180°

(jω
c
)=-180°-arctanω
c
-arctan10ω
c
=-331.9

,则
(jω
c
)=arctan2ω
c
-90°-arctan5ω
c
=-257.24°
