Using Octave or MATLAB

Given the non-linear system:

dx/dt= y

d2x/dt2= Z

d3x/dt3= gain*x-a1*y-a2*z-gain*(x3)

gain= 1.8

a1= 1.25

a2= 1

x= 0

x2= 0.001

x3= 0

-Plot x versus time for 200 seconds.

-For the non-linear system above, create a phase plane of xdot (dx/dt) versus x.

-For the non-linear system above, create a phase plane of xdot (dx/dt) versus x for three different initial conditions (x2=0.001:0.001:0.003). Plot each of the three solutions using different colors onto the same plot.