(t)=412e+A2 R i(t) U(0)=0→>0=41+42 6g71F do i(0)=10A一 e-642 dt Re f dudu d t dt t=0 Cs←(0)+i(0)i(0) 420 or-41-642=420∴41=84,A2=-84 N84e- U(t)=84(e--e" 84 d let 84(-e-+6e)=0 +6e 0→e 6 At time t the voltage becomes maximum 0.358s→m=48.9 5t t A e A e dt d i A 6 10 1 6 2 (0) − − = → = − −  420 (0) (0) (0) (0) 0 = = + = = = =  C i C i i C i dt t d dt d i C c R c   t e e V t t ( ) 84( ) − −6  = − A1 = 84, A2 = −84 : 84( 6 ) 0 6 = − + = −t − t e e dt d let  t e − 84 t e 6 84 − − t  m t At time tm the voltage becomes maximum. t s V e e e m m t t t m m m 0.358 48.9 5 ln 6 6 0 6 6 5 = = → = − + = → = − −  0 0 1 2 (0) = → = A + A or − A1 − 6A2 = 420 R i c i 6 i(t) 7H F 42 1  Re f t t t A e A e 6 1 2 ( ) − −  = +