Consider the equation

If you type this in at the equation box, then you will see that you have two variables to work with, namely the independent variable t and the dependent variable t.
You may plot these by using the display dialog box to specify t as the variable for the horizontal axis, and x as that for the vertical axis.
Now double-click the right mouse button anywhere in the resulting display to see the graph of a solution to the differential equation

Wed Sep 30 15:21:52 PDT 1998