Question

隐函数求导怎么弄？用mathematica……

Answer 1

给个我自己的例子给你，其中ri
即为隐函数，变量为t.
多看看帮助文档吧，少年。
NDSolve[{
\!\(\*SuperscriptBox["\[Theta]i",
"\[Prime]",
MultilineFunction->None]\)[t]
==
dir*
p\[Theta][ri[t],
\[Theta]i[t]],
\!\(\*SuperscriptBox["ri",
"\[Prime]",
MultilineFunction->None]\)[t]
==
dir*
ri[t]
pr[ri[t],
\[Theta]i[t]],
\[Theta]i[0]
==
\[Theta]0,
ri[0]
==
r0},
{\[Theta]i,
ri},
{t,
0,
tend},
MaxSteps
->
2000]