## 90 Reputation

11 years, 271 days

## why Error, (in dsolve/numeric/SC/IVPsetu...

Maple

ex1 := {
diff(x1(s),s\$2) - 2/x2(s)*diff(x1(s),s)*diff(x2(s),s) = 0,
diff(x2(s),s\$2) + 1/x2(s)*diff(x1(s),s)^2-1/x2(s)*diff(x2(s),s) = 0
};
sol := dsolve(ex1);
ic := {x1(0)=0.1, x2(0)=0.1};
dsol := dsolve(ex1 union ic, numeric, range=0..1);
odeplot(dsol);

Error, (in dsolve/numeric/SC/IVPsetup) initial conditions must be numeric

initial condition has already set 0.1 but still ask for must be numeric why?

## why pdsolve have found functions with sa...

when try to solve this pde, got error

i know function h already, just try to guess its pde, initial value condition is calculated from known function

motion := {diff(h(x1,x2), x1)^2 + 2*diff(h(x1,x2), x1)*diff(h(x1,x2), x2) + diff(h(x1,x2), x2)^2 = 0};
ic := {h(1,x2)=ln(1-x2-(1/2)*c),h(x1,0)=ln(1-(1/2)*c*x1)/x1};
monster := pdsolve(motion union ic);

Error, (in pdsolve/sys/info) found functions with same name but depending on different arguments in the given DE system: {h(1, x2...

## what is the command to change transfer m...

Maple

what is the command to change transfer matrix to state space?

## how to calculate force of lagrangian in ...

Maple

L include kinetic energy

when F = diff( diff( L, dx), t) - diff(L,x)

i need to diff L with respect to dx, however, there is no dx in maple, how to do above equations?

## How to use ExteriorDerivative correctly...

Maple

with(DifferentialGeometry):
DGsetup([x],M):
ExteriorDerivative(x^2);

invalid frame: DGframe_data[0][1][2]

how to diff x^2 to get 2*x*dx with above command?

 First 15 16 17 18 Page 17 of 18
﻿