(1),IBQ=(VCC-UCE)/RB=11.3/280K≈40uA
ICQ=IBQ*β=2.4mA
VCEQ=VCC-ICQRC=12V-2.4mA*3K=4.8V
(2),Au≈-βRC/rbe
(3),Ri=RB//rbe
(4),Ro=RC
(1),IBQ=(VCC-UCE)/RB=11.3/280K≈40uA
ICQ=IBQ*β=2.4mA
VCEQ=VCC-ICQRC=12V-2.4mA*3K=4.8V
(2),Au≈-βRC/rbe
(3),Ri=RB//rbe
(4),Ro=RC