Theorem 21
When
is continuous and satisfies a Lipschitz Condition in the variable
on the domain
.
Assume a constant
exists such that
for all
in
,
and let
be the unique solution to the initial value problem
,
and call
the successive approximations generated by Euler's method for some positive integer
.
Then for each
, we have
Proof
The major problem with a practical application of this theorem is that one does not normally knows the second derivative of
in advance. Sometimes, one can find it as
.
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