... dieu hoir theo phr-rong thing 16: MQt sqi oav nra"r-, a* -noi, '6, d6,n10Hz song tao thdnh lan trtryAn tron day voi van dirrig voi tAn s6 f thay doi duoc khoin gtu 45Hz dao dQng ngtrgc pha v6i ... th6 tuc thdi giira hai didm A, N lQch pha mot goc lir ,/L so voi hiQu dien th6 tirc thoi giira /L so vo'i pha mQt g6c ld irai di€m M, B, d6ng thoi cubng d0 ddng diQn tirc thoi ch4y mach chdm ... cirm Ls mic nOi tiep hai dAu A,B cira doan m4ch ndy mQt hiqu dign th6 xoay chi6u u = Uscos(ot - 7T voi mdt hdp den X DAt 7r dong di0n trlc thoi chay mach i : Iecos(cot + lr ;b ) (A) H6p den X co...