例3交、直流共存的电路(续) 2+L4 6 )tC tR,oR123=1+10sm(1000459)V B3=P3直+P3交 R R 12(5√2) =25.5mW 2 思考:如何求电容两端的电压uc?例3.交、直流共存的电路(续) u + C - V1 V2 R2 R1 R3 3 u 1 10sin(1000 45 )V 3 3 3 = + + = + t u U u 25.5mW 2 (5 2) 2 1 2 2 3 2 3 3 2 3 3 3 3 = + = + = + = R U R U P P 直 P 交 思考:如何求电容两端的电压uC? + - uC