, ?
( ), plop , , .
, , .
. , - , .
, , , ( , ) .
n D*(n-2), D. f(start)=y_0, f(end)=y_n, f'(start) = f'(end) = 0) :
f_n(between n and n+1) = f_n+1(between n and n+1)
f'_n(between n and n+1) = f'_n+1(between n and n+1)
...
( f(point n) = y_n f'(point n) = 0, ( ).
( DoF, ?). f''(start) = 0..., .
, , , .
.