Systèmes différentiels - Notions de base

\(\displaystyle{\left\{\begin{array}{llll}x''=-\frac{Kx}{(x^2+y^2+z^2)^{3/2}} \\ y''=-\frac{Ky}{(x^2+y^2+z^2)^{3/2}} \\ z''=-\frac{Kz}{(x^2+y^2+z^2)^{3/2}}\end{array}\right.}\)

\(\displaystyle{\left\{\begin{array}{llll}x' & = & u \\ y' & = & v \\ z' & = & w \\ u' & = & -\frac{Kx}{(x^2+y^2+z^2)^{3/2}} \\ v' & = & -\frac{Ky}{(x^2+y^2+z^2)^{3/2}} \\ w' & = & -\frac{Kz}{(x^2+y^2+z^2)^{3/2}}\end{array}\right.}\)