R 1()=i1(0)+[i1(04)-i1(∞le 十 L了u1(+8 =3.5-2.5e U,(t)=L"(t)1002 e 3 dt 3 (t) 100 3.5R1 R2 IS R3 S + Us - iL(t) + uL(t) - L t t L L L L e i t i i i e 3 2 0 3.5 2.5 ( ) ( ) [ (0 ) ( )] −  − + = − =  + −  t L L e dt di t U t L 3 2 0 3 ( ) 100 ( ) − = = 0 1 3.5 iL(t) t 0 uL(t) t 3 100