Solution 13886: Calculating Implicit Derivatives on the TI-89 Titanium and Voyage™ 200 with OS v3.10. or Higher.
How can I calculate implicit derivatives on my TI-89 Titanium or Voyage 200 with OS v3.10 or higher installed?
With the release of OS v3.10, the impDif() function has now been added to the operating system of the TI-89 Titanium and Voyage 200. The impDif() function can be accessed by following the steps provided below.
1) From the HOME screen, access the Calc menu by pressing [F3]
2) Select D:impDif(
1) From the HOME screen, access the MATH menu by pressing [2nd] 
2) Selct B:Calculus and then D:impDif(
The syntax for the impDif() function is listed below:
impDif(equation, independentVar, dependentVar [,order]).
Please Note: The order value is optional. If a value is not given for order, the calculator will use a default value of 1.
Below is an example of using the impDif() function on the TI-89 Titanium calculator:
Please see the TI-89 family, TI-92 family and Voyage 200 guidebooks for additional information.