# difference engine.

Difference Engine
Weierstrass:
A machine to compute mathematical tables

–	 Any continuous function can be approximated by a
polynomial
–	 Any Polynomial can be computed from difference tables

$
int{(n)} = n^{2}+n+41 \
d1(n) = int{(n)} - int{(n-1)} = 2n \
d2(n) = d1{(n)} - d1{(n-1)} = 2 \
$

Make a Table with the equations.
You can use Addition and Find the next value of function for a new “n”.

source : http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-823-computer-system-architecture-fall-2005/lecture-notes/