Question

mathematica 如何将方程组化简为矩阵的形式

如图，如何将T1,T2化为这种形式，求出D1,D2,D3,D4

T1=\!\(
\*SubsuperscriptBox[\(L\), \(1\), \(2\)]\ \((
\*SubscriptBox[\(m\), \(1\)] +
\*SubscriptBox[\(m\), \(2\)])\)\ \(\*
SuperscriptBox[
SubscriptBox["\[Theta]", "1"], "\[Prime]\[Prime]",
MultilineFunction->None][t]\)\) +
Subscript[L, 2] Subscript[m,
2] (-g Sin[Subscript[\[Theta], 1][t] + Subscript[\[Theta], 2][t]] +
Subscript[L,
2] ((Subscript[\[Theta], 1]^\[Prime]\[Prime])[t] + (
Subscript[\[Theta], 2]^\[Prime]\[Prime])[t])) +
Subscript[L,
1] (-g Sin[
Subscript[\[Theta], 1][t]] (Subscript[m, 1] + Subscript[m, 2]) -
Sin[Subscript[\[Theta], 2][t]] Subscript[L, 2] Subscript[m, 2]
Derivative[1][Subscript[\[Theta], 2]][
t] (2 Derivative[1][Subscript[\[Theta], 1]][t] +
Derivative[1][Subscript[\[Theta], 2]][t]) +
Cos[Subscript[\[Theta], 2][t]] Subscript[L, 2] Subscript[m,
2] (2 (Subscript[\[Theta], 1]^\[Prime]\[Prime])[t] + (
Subscript[\[Theta], 2]^\[Prime]\[Prime])[t]))
T2=Subscript[L, 2] Subscript[m, 2] (-g Sin[
Subscript[\[Theta], 1][t] + Subscript[\[Theta], 2][t]] +
Subscript[L,
1] (Sin[Subscript[\[Theta], 2][t]] Derivative[1][
Subscript[\[Theta], 1]][t]^2 +
Cos[Subscript[\[Theta], 2][t]] (Subscript[\[Theta],
1]^\[Prime]\[Prime])[t]) +
Subscript[L,
2] ((Subscript[\[Theta], 1]^\[Prime]\[Prime])[t] + (
Subscript[\[Theta], 2]^\[Prime]\[Prime])[t]))





Answer 1

一般来说两个方程解不出来四个未知数