Looking for a function in system of DE

1. Jun 3, 2014

sludger13

I'm looking for prescription of function $f$ with behavior:

putted in this system of DE solving some simple functions $r_{1}(x)$ and $r_{2}(x)$:
$\frac{d^{2}r_{2}(x)}{dx^{2}}=\frac{f(r_{2}(x)-r_{1}(x))}{C}$
$\frac{d^{2}r_{1}(x)}{dx^{2}}=-\frac{f(r_{2}(x)-r_{1}(x))}{K}$

$r_{2}(x)-r_{1}(x)>0;f(r_{2}(x)-r_{1}(x))>0;C,K>0$

Attached Files:

• graf.png
File size:
5.2 KB
Views:
173
Last edited: Jun 3, 2014
2. Jun 3, 2014

maajdl

Why not a straight line?

3. Jun 3, 2014

maajdl

3.31143 - 1.37286 x + 0.135714 x^2

fits more or less the lower curve