|
| |
| In
the system (3) we take |
dt
|
as
a free variable , then if |
|
da
|
|
| A = |
|
| df1 |
... |
df1 |
| dx1 |
|
dxn
|
|
... |
|
| dfn
|
... |
dfn |
| dx1 |
|
dxn |
|
|
and
| Ai = |
|
| df1 |
... |
f10
|
...
|
df1 |
| dx1 |
|
|
|
dxn |
| ... |
|
i |
|
|
| dfn |
... |
fn0
|
... |
dfn |
| dx1 |
|
|
|
dxn
|
|
|
* |
|
| then
by the Cramer rule we have |
dxi |
= |
Ai . |
|
da |
|
A , |
| If we take |
dt = A , |
then we have
the system |
|
da |
|
|
| |
|