1，解：设流过R1的电流为i1(t)，流过R2的电流为i2(t)
则：u1(t)=R1i1(t)+1/C1∫[i1(t)-i2(t)]dt
1/C1∫[i1(t)-i2(t)]dt=R2i2(t)+u2(t)
u2(t)=1/C2∫i2(t)dt
对上式进行零初始条件拉氏变换得：
U1(s)=R1I1(s)+1/C1s[I1(s)-I2(S)]
1/C1s[I1(s)-I2(s)]=R2I2(s)+U2(s)
U2(s)=1/C2s(s)
消去中间变量I1(S),I2(S)，得系统的传递函数为：
G(s)=U2(s)/U1(s)=1/R1R2C1C2s+(R1C1+R2C1+R1C2)s+1