因為用打的不清楚 附上縮圖http://ppt.cc/sJJj
謝謝
sf=[kf/(af+bf+cf)]開根號
sc=[kc/(ac+bc+cc)]開根號
s=[k/(a+b+c)]開根號
BIFA = BesselI[1, sf*r] /. r -> a;
BICA = BesselI[1, sc*r] /. r -> a;
BKCA = BesselK[1, sc*r] /. r -> a;
BICB = BesselI[1, sc*r] /. r -> b;
BKCB = BesselK[1, sc*r] /. r -> b;
BISB = BesselI[1, s*r] /. r -> b;
DBIFA = D[BesselI[1, sf]*r], r] /. r -> a;
DBICA = D[BesselI[1, sc]*r], r] /. r -> a;
DBKCA = D[BesselK[1, sc]*r], r] /. r -> a;
DBKSB = D[BesselK[1, sc]*r], r] /. r -> b;
DBISB = D[BesselI[1, s*r], r] /. r -> b;
DF,DC,EC,LC 為待解的變數
eq1 = (DF*BIFA) == (DC*BICA + EC*BKCA)
eq2 = (DC*BICB + EC*BKCB) == (Z*BISB)
eq3 = LF*(sf*DF*DBIFA - 1/2) ==LC*(sc*DC*DBICA +sc*EC*DBKCA - 1/2)
eq4 = L*(s*Z*DBISB - 1/2) == LC*(sc*DC*DBISB +sc*EC*DBKSB - 1/2)
Solve[{eq1, eq2, eq3, eq4},{DF,DC,EC,LC}] // Simplify
這樣的方法可以求解這四個未知嗎??
因為跑下去跑了很久都還在RUN 想必是BESSEL的問題