Differentiate
times, from which we can express
and
as linear combinations of
and
(see
(6.72), (6.73) for
).
Differentiate
times and project the resulting vectors onto the normal vector
,
from which we obtain a linear equation in
,
,
,
(see (6.76) for
). Substitute
and
, which are obtained from Step 1, into the resulting
equation.
Another additional linear equation is obtained from
, where
is the
-
order
derivative of
and
is defined in
(6.47) and depends exclusively on
and
and
their derivatives (see (6.76) for
).
Solve the linear system for
) and
substitute them into the expression of
in Step 1.