Chapter 27, Problem 22P

Use MATLAB or Mathcad to integrate

$\begin{array}{l}\frac{dx}{dt}=-\sigma x+\sigma y\\ \frac{dy}{dt}=rx-y-xz\\ \frac{dz}{dt}=-bz+xy\end{array}$

where $\sigma =10,b=2.666667\text{ and }r=28$. Employ initial conditions of $x=y=z=5$ and integrate from $t=0\text{ to 20}$.