Press the add button after you enter the values for each equation.
Create the system after all equations have been entered. The variables used to
define the first two rate equations will be plotted on the horizontal and
vertical axes, respectively. For example, the rate equations for radioactive decay
can be scripted as follows:

Variable

Initial Value

Rate

t

0

1

n

100

-0.1*n

The time variable will usually have a rate of unity since dt/dt=1. The
initial number of radioactive particles is set to 100. Approximately 10%
of these particles will decay during every time unit.

Second order ODEs can be rewritten as a coupled system of first order differential
equations. For example, the system of differential equations that describe
a simple harmonic oscillator can be written as:

Variable

Initial Value

Rate

t

0

1

x

1

v

v

0

-2*x

The graph will display x(t) if the equations are entered in the same order as
they appear in the table. Reverse the order of the last two equations to
display v(t).