Hiroshi Sakuta 
Nov.7,1997
The fomula of Euler method in 1st order
differential equation is
SCHEME 0 (first order)
where advances a solution from 
to
.( 
)
Runge-Kutta method can improve the solution by
additional operation at 
.
SCHEME 1 (second order)
SCHEME 2 (fourth order)
These schemes can be extended to the vector space.
