Texas Instruments TI-89 Titanium Manual page 14

The command that will let you solve first and second order
differential equations is deSolve.
First order example: y'= y+x^2
•
Step 1 To enter in deSolve, press F3. Continue down until
you reach "C:deSolve."
•
Press enter and it will appear on the home screen.
• Step 2 Enter in the equation as: deSolve (y'= y+x^2,x,y).
Press enter.
•
Step 3 The answer given is the general solution y=@1*e^x-
x^2-2x-2. Thus @1 stands for an arbitrary parameter (that
we usually write as c or c1.)